The current literature commonly discusses four distinct communication barriers: language, cultural, psychological, and MMDs. They form the analytical backbone of this review and are classified and further explored in this subsection. Each barrier is examined in turn, with attention to its defining characteristics and the clinical context in which it most commonly manifests.

Language barriers between patients and clinicians remain a foundational threat to safe and effective care (Table 1). When the clinician and patient do not share a common tongue, the probability of diagnostic inaccuracies, medication errors, and diminished therapeutic alliance rises sharply [46-57]. Even among bilingual encounters, nuanced clinical terminology can be lost, and patients often resort to a rote agreement rather than clarifying doubts, thereby masking unresolved concerns [53-59]. This dynamic becomes more complicated due to systemic factors. Research shows that LEP mothers often feel abandoned by the health care system. They deal with long wait times and staff who lack cultural understanding while trying to navigate complex institutions to obtain diagnoses and services for their children [60]. Studies of nonnative English speakers further show that LEP systematically reduces comprehension of illness trajectories and adherence to treatment recommendations, ultimately widening health-outcome disparities [50,61-68]. This situation makes patients feel powerless. In adult acute care settings, patients often mention language barriers as their main frustration. They point out that ignoring cultural customs can create feelings of racism and exclusion [69].

In the absence of qualified language services, many encounter default to ad hoc solutions—most commonly family members, untrained staff, or informal community volunteers. Such substitutions increase the risk of omitted symptoms, distorted risk explanations, and breaches of confidentiality [51,53,109,146,154,156,160-162]. In neonatal care, informal interpretation by multilingual health care staff shows limited formal support. While empirical analyses of emergency departments and rural clinics show that untrained interpreters nearly double error rates in medication reconciliation and consent [150,155,157,163]. The serious effects of these communication gaps were clearly shown during the COVID-19 pandemic. Communication problems in critical care, worsened by isolation and mechanical ventilation, required simple, low-tech teamwork between nurses and speech-language pathologists to ensure basic communication between patients and providers [75].

Compounding the problem, many regions face chronic shortages of professional interpreters, a gap that becomes acutely visible during off-hours and high-acuity scenarios [146,161,164,165,167]. As health care shifts more to digital platforms, older adults with language barriers face a double challenge. They deal with both language issues and technology exclusion, making it hard to connect with care teams through telehealth services [80]. These shortages undermine quality-of-care metrics and intensify clinician stress, especially when rapid, high-stakes decision-making is required [146,161,163,168,169].

Beyond language, cultural frames influence how information is delivered, interpreted, and acted upon (Table 2). Conflicting belief systems regarding disease etiology, family authority, and preferred healing practices can derail shared decision-making unless clinicians actively negotiate meaning [53,63,105,109,116,172-175]. Menopausal women may avoid discussing sexual health because they believe that unmarried or younger providers cannot understand their traditional marital duties [86,176]. In another case, older adult Arab patients felt that their cultural and religious beliefs were not understood, which led to health services being seen as less effective [123]. Similarly, patients with breast cancer identified ingrained cultural beliefs as a key barrier to discussing sexual health [177]. Even ostensibly simple nonverbal cues, such as eye contact duration, tone, or gestures, carry divergent connotations across cultures, sometimes signaling disrespect when none is intended [52,109,178,179]. This challenge increased during the COVID-19 pandemic, when personal protective equipment obscured facial expressions. Clinicians had to depend on basic “proxy” methods such as shouting or using gestures, often weakening rapport [85]. Additionally, the quick move to audio-only telehealth has further damaged these nonverbal connections. This change has hit vulnerable patients hard, as they often need visual cues to understand empathy and trust [91]. Furthermore, norms around disclosure and deference to medical authority differ markedly; some patient communities expect paternalistic guidance, whereas others prioritize egalitarian dialogue [51,180-184]. In acute care, patients with limited English skills often feel “powerlessness” when providers overlook cultural practices, such as family-centered decision-making. The neglect is often interpreted as racism [69]. Effective engagement with immigrant communities often requires trusted faith-based or community networks rather than reliance on traditional clinical authority alone [98,184,185]. Unless these implicit rules are surfaced and reconciled, misalignments in expectations and decision roles persist, thereby perpetuating treatment delays and dissatisfaction [186,187]. Similarly, the rapid move to audio-only telehealth has damaged nonverbal connections, disproportionately affecting vulnerable patients who rely on visual cues to gauge empathy and establish trust [51,184,185].

Fear and anxiety emerge as potent inhibitors of patient‐initiated dialogue during clinical encounters (Table 3). This leads to patients avoiding questions, underreporting pain, or withholding discomfort details, thus compromising diagnostic accuracy and shared decision-making [63,114,204-206]. This reluctance is particularly strong among vulnerable groups. For instance, Brazilian immigrants, whose mistrust of authority can limit health service engagement [98]. Qualitative observations in oncology and surgical settings show that heightened procedural anxiety fuels silence, which in turn amplifies uncertainty and stress, ultimately reinforcing the original fear [207]. These findings underscore the need for anticipatory counseling and structured question prompts that normalize patient participation before anxiety has a chance to escalate.

The stigma surrounding mental illness compounds this communicative reticence. Patients who internalize cultural or societal prejudice against psychiatric disorders frequently mask depressive symptoms, avoid admitting substance-use histories, or downplay stress levels, thereby limiting clinicians’ ability to form holistic treatment plans [63,111,117,187,214]. For mothers of children with autism and limited English skills, this stigma can compound feelings of abandonment and limited access to support networks [60]. Likewise, during the Ukrainian refugee crisis, stigma and low mental health awareness kept traumatized people from obtaining the available psychosocial support [84].

The effect intensifies under emotional overload, acute periods of crisis, or high-stress hospitalization, when cognitive bandwidth narrows, and expressive capacities falter [169]. This was clearly shown during the COVID-19 pandemic, when critically ill patients on mechanical ventilation experienced “extreme frustration and fright.” They needed simple, low-tech solutions from speech pathologists just to express their basic needs [75,221,222]. In less urgent but still significant situations, low-income women with gestational diabetes found information from their providers to be “overwhelming.” Anger is also seen in a study of 22 Israeli oncologists [220] where patients with cancer and their family are unable to deal with the realities of cancer treatments. This led to a breakdown in communication, as they struggled to process actionable advice because of the overwhelming number of medical instructions [219]. Emergency department interviews demonstrate that distressed patients offer disjointed narratives, omit chronological details, and struggle to prioritize symptoms, leading to mistreated acuity and longer lengths of stay [194,218]. Interventions that combine destigmatizing language with phased, guided questioning have shown promise in recovering essential information under these conditions.

Even outside overt crises, embarrassment, fear of judgment, or low self-confidence consistently predict reduced communication quality. This leads to shorter responses and the use of more hedging phrases, both of which clinicians can misinterpret as disinterest [104,111,224,225]. Concurrently, a lack of psychological safety, such as perceived permission to speak candidly without ridicule or dismissal, erodes trust and discourages disclosure of sensitive issues such as nonadherence or complementary-medicine use [143,209,227]. Case-control data from primary-care clinics indicate that establishing clear “permission statements” (“many patients find this topic awkward…”) nearly doubles rates of honest reporting [186,226].

Gaps between clinicians’ diagnostic logic and patients’ lay reasoning erode trust and foster decisional paralysis (Table 4). When pathophysiology is explained through jargon-laden narratives or abstract probabilities, patients often fail to grasp causal links between test results and prescribed regimens, leading to confusion, lowered adherence, and a perception that decisions are opaque or arbitrary [111,206,220,227,236]. Patients in acute care often express a feeling of “powerlessness” when complex medical explanations cause them to feel left out of the decisions that affect their health outcomes [69]. These “reasoning gaps” encourage patients to seek confirmatory information from less reliable sources, which can weaken subsequent consultations [143,237,238]. In telephone-only telehealth, the loss of visual cues makes it harder for clinicians to confirm understanding [91]. Explicitly mapping diagnostic steps with plain-language analogies or decision aids has been shown to restore shared understanding and rebuild confidence in the clinical process [239].

Misaligned assumptions about disease etiology and responsibility for follow-through create a second layer of mismatch. Patients may emphasize social stressors or spiritual causes, while clinicians foreground biomedical mechanisms. Similarly, providers may assume that patients will self-monitor symptoms or adjust lifestyle factors, whereas patients expect directive, clinician-led management [168,200,206,220,244]. Patients often have differing assumptions about technology use and the roles of providers [111,245]. Ethnographic data demonstrate that these divergent premises generate conflicting action plans, stalled referrals, and breakdowns in medication titration [237,244]. Structured elicitation of patients’ causal beliefs has been correlated with higher concordance in goal setting and a measurable reduction in follow-up ambiguities [238,239].

Expectation conflicts finally surface when patients anticipate rapid symptom relief while providers pursue incremental, long-term disease control [63,200,206,220,245]. Postoperative pain management, chronic disease titration, and behavioral-change interventions are particularly susceptible to this tension: patients equate therapeutic success with immediate absence of discomfort, whereas clinicians focus on gradual stabilization or prevention of relapse [33]. In one study, oncologists found that patients had unrealistic expectations in terms of treatment outcomes [220], which resulted in a communication breakdown.

Longitudinal surveys show that uncorrected expectation gaps predict lower satisfaction scores, premature discontinuation of therapy, and a rise in “doctor-shopping” behaviors [207,249]. In maternity care, the belief that regular translation services are enough often conflicts with the actual needs of women. They expect a more collaborative and culturally connected way of communicating. This requires bicultural research assistants to fill the gap that standard interpreters cannot cover [83]. Conversational techniques that surface timelines explicitly, for example, “What improvements would you hope to see by next month?” significantly narrow these discrepancies and enhance adherence, particularly in multicultural settings where cultural time horizons vary [36,194].

After identifying the various barriers that impede communication between patients and providers, it is important to understand the impacts of these barriers. This subsection addresses how these barriers affect patient care and health outcomes. A summary of the observed impacts across emotional, clinical, and systemic domains is presented in Table 5.

Linguistic barriers, such as LEP and lack of access to professional interpreters, directly undermine patient comprehension. Patients may misinterpret diagnoses, treatment instructions, or follow-up plans, leading to emotional withdrawal and heightened anxiety [29,103,166]. This isolation is especially strong for older immigrants. Research shows that older adult patients with language barriers often experience a “double burden” of being cutoff from both language and digital resources. This situation makes it hard for them to access telehealth services or understand medication management without depending heavily on family members [80]. Language discordance has also been linked to delayed care-seeking and missed appointments, as patients feel ill-equipped to articulate their needs [14,15,61]. Moreover, language difficulties can hinder accurate diagnosis and shared decision-making, contributing to clinical errors [62,272,273]. Cultural barriers exacerbate these issues by creating mismatches in expectations and values. For example, culturally rooted discomfort in discussing illness with providers of a different gender or preference for family-centered decision-making may inhibit transparency during consultations [86,176]. These dynamics delay engagement with care, reduce adherence, and generate systemic inefficiencies [51,62,256].

Psychological barriers, including stigma, anxiety, and emotional overload, particularly affect patients dealing with chronic or mental health conditions. These patients may withhold critical information, leading to misdiagnosis and treatment delays. Research on HIV prevention indicates that fear of social rejection stops at-risk groups from obtaining the treatments they need, indicating the need for both clinical and focused efforts on building trust in the community to be effective [93]. Emotional distress also impairs memory and verbal communication during clinical encounters, diminishing both patient experience and diagnostic clarity [220]. MMDs further complicate communication. These mismatches undermine trust, disrupt shared decision-making, and increase patient dissatisfaction. Patients may misinterpret medical reasoning as dismissive or unresponsive, leading to poor adherence and repeated consultations [33,206,262]. A clear example of this is seen in chronic pain management. Patients often want immediate relief, following the “cure” model. In contrast, clinicians concentrate on functional improvement, using the “management” model. This unrecognized difference causes mutual frustration, prompting “doctor shopping” and damaging the therapeutic relationship [87].

After identifying the key communication barriers and their consequences, we now turn to the interventions developed to mitigate them. This section examines the intervention strategies that have been implemented to address communication barriers and identifies which barrier types they primarily target. Drawing from the literature, we categorize these interventions and their targeted barriers and depict them in Table 6.

Professional language‐service interventions remain the most consistently validated strategy for mitigating communication breakdowns with LEP populations. Evidence shows that trained interpreters reduce diagnostic errors, improve satisfaction, lower readmissions, and support better maternal and patient outcomes compared with ad hoc or family interpreters [14,15,146,150]. Bicultural research assistants may further improve engagement when language and cultural needs intersect [83]. Decision-analysis models further indicate that interpreter use yields cost savings through shorter lengths of stay and fewer duplicate tests, largely because accurate histories are obtained on first contact [272]. Complementary AI-based multilingual translation tools extend this reach to low-resource or time-critical settings, with early trials demonstrating rapid phrase-level accuracy above 90% for high-volume languages, though performance drops in idiomatic or domain-specific contexts [280]. The emerging consensus is that hybrid models, professional interpreters for complex consultations, and vetted machine translation for routine exchanges, optimize both cost and clinical fidelity [49-52,161,175,281].

Emerging health care AI shows the shift from basic translation tools to “AI notetaking” agents that can translate and organize clinical notes in real-time [110,175]. These tools aim to lessen the administrative stress that often causes rushed and low-quality communication in multilingual environments. Additionally, hybrid methods that combine large language models with traditional Bayesian networks are now more accurate than human psychologists in certain vignette-based diagnostic tasks. This suggests a future where AI serves as a backup to help avoid communication-related diagnostic mistakes. AI-powered chatbots offer a scalable front line for triage and information dissemination, particularly in multilingual or resource-limited environments. Importantly, chatbot interfaces equipped with real-time translation and culturally adaptive scripts demonstrate higher engagement rates among LEP users than static FAQ (frequently asked question) pages [277]. Nevertheless, concerns persist regarding diagnostic accuracy, bias propagation, and data privacy, underscoring the need for rigorous validation against gold-standard clinical protocols [57,277]. Ongoing research and development is focusing on integrating fallback loops with human clinicians and incorporating evidence-based symptom-checker algorithms to enhance reliability [278].

Cultural barriers often arise from mismatched values, health beliefs, or discomfort tied to identity differences. These challenges are best addressed through cultural competency training that combines classroom instruction with hands-on experiences. Cultural competency interventions improve providers’ ability to align care with patients’ sociocultural contexts, thereby enhancing trust, communication quality, and care equity [50,175,183]. Programs featuring community immersion and scenario-based simulations have been shown to improve medication adherence and follow-up rates in ethnically diverse groups. These outcomes are largely driven by increases in perceived clinician trustworthiness [282]. For example, a mixed-methods study of Indian physiotherapy students found that a targeted cultural competency training program significantly improved therapists’ ability to engage in patient-centered care, leading to a measurable increase in perceived treatment adherence [294]. Participatory and system-level approaches further demonstrate that culturally responsive service design can address structural barriers and improve engagement among underserved populations [53]. Recent cluster trials applying intersectional frameworks, which account for overlapping identities such as race, gender, and socioeconomic status, have further enhanced shared decision-making outcomes, especially in chronic disease management [283]. Qualitative research backs this approach by showcasing the unique needs of specific groups. For example, African American, Hispanic, and Appalachian women with a history of gestational diabetes all said that communication with providers often felt “overwhelming” and did not provide practical advice. This suggests that interventions should be designed to address not only cultural backgrounds but also the specific socioeconomic challenges, such as cost and transportation, that these groups face together [219]. Notably, evidence suggests that sustained, context-specific training yields more durable improvements than one-time workshops, highlighting the need for long-term institutional investment in cultural responsiveness.

Interventions that target provider attitudes and emotional responsiveness, particularly empathy training, are central to addressing psychological barriers such as stigma, fear, and emotional reluctance. Structured empathy training can reduce stigmatizing language, increase the likelihood of mental health referral uptake among marginalized patients, and strengthen reflective listening [70,215,285-289]. By fostering a safer emotional environment, such training improves disclosure of sensitive issues, particularly in stigmatized contexts. For people who inject drugs, having a “trusted doctor,” defined by nonjudgmental communication and emotional safety, was the strongest predictor for seeking timely care for soft tissue infections [217].

MMDs often arise from misaligned expectations, reasoning styles, or divergent understandings of illness between patients and health care providers. To bridge these gaps, clinicians should use clear, direct language and avoid medical jargon, acronyms, or idiomatic expressions. Using short sentences with frequent pauses can facilitate information processing, particularly in interpreted encounters [144]. Verbal explanations should be supplemented with visual aids, such as diagrams, illustrated instructions, or step-by-step graphics, to enhance patient comprehension [70,144,251]. However, even these tools must be designed with the user’s mental model in mind. A notable example comes from maternal health programs in Nigeria [229]. Researchers found that simply copying Western information formats did not work for women with low or no literacy. Instead, successful programs needed a community-based design process. This approach treated these women not just as patients, but as co-designers who could shape the information to fit their communal ways of understanding [229]. These strategies are particularly beneficial for individuals with limited health literacy or limited familiarity with biomedical concepts [144,195,291]. Evidence from decision-aid trials in primary care indicates that aligning patient and provider mental models through visual communication and iterative teach-back methods significantly reduces diagnostic errors and increases concordance in treatment planning [272,273]. In maternity care, this connection works best through “reflexive collaboration.” Bicultural research assistants help close the gap between clinical protocols and the real experiences of women with limited English skills. This ensures that the “care partnership” is more than just a policy ideal; it becomes a practical reality [83].

Finally, wearable devices and remote-monitoring platforms present a complementary avenue for circumventing verbal, cultural, psychological, and cognitive barriers by privileging objective, continuous physiologic data. Studies in cardiac and diabetic populations reveal that real-time telemetry, transmitted directly to care teams, reduces unscheduled hospital visits by up to 25% and facilitates earlier intervention independent of patients’ communicative proficiency [293]. The latest generation of wearables integrates haptic alerts and multilingual smartphone dashboards, allowing patients to interpret feedback in their preferred language while clinicians receive standardized data streams [292]. This will significantly help reduce communication barriers as patient data will be readily available to doctors. As a result, the context of the patient’s illness can be more easily understood, especially with the help of AI models. Thus, as interoperability standards and AI capabilities develop, these technologies are set to become key parts of overall plans that tackle all aspects of communication barriers.

The review shows a steady rise in publications about communication barriers in health care, which increased markedly from 2021. This surge in research activity coincides with the onset of the COVID-19 pandemic, which intensified global scrutiny of systemic weaknesses in health care, including the critical role of communication barriers [161,295]. The trend reflects a growing recognition of communication as a key determinant of health care quality and an area ripe for interdisciplinary investigation [60].

This review breaks down communication barriers into four main types: language, cultural, psychological, and MMDs. Each type highlights specific but overlapping causes of problems in patient-provider interactions. While the focus of the literature has largely been on language and cultural barriers, there has been a growing body of research on how MMDs and psychological barriers may manifest as communication barriers in health care [49,50]. The distribution highlights an opportunity for more balanced, multifaceted research agendas that move beyond language proficiency to capture the full spectrum of communicative impediments in clinical care.

Interestingly, while distinct communication barriers exist, they do not seem to be linked to specific clinical or emotional outcomes. Instead, multiple barriers often happen together and contribute to negative experiences. For example, studies have found that patients dealing with both language and psychological challenges often report poor interactions with their health care providers [51,158,218,251]. These overlapping barriers can also delay the decision to seek care, as patients may avoid medical visits due to fear, stigma, or difficulty in communicating effectively [52,60]. Notably, patients in acute care settings frequently describe a profound sense of “powerlessness” when linguistic barriers combine with cultural oversight [69,183]. In the context of managing chronic diseases, differences in mental models and cultural beliefs make care more complicated. Patients who believe their illness has spiritual causes may dismiss biomedical explanations, leading to low adherence and disengagement [260-262]. Therefore, communication barriers, regardless of their type, often lead to clinical and emotional effects. This highlights the need to address them in a unified and thorough way. Our analysis in this provides a high-level overview of reported impacts; however, future reviews should distinguish among patient-, clinician-, and system-level outcome domains to build a more nuanced understanding [61]. Such stratification would require different data extraction procedures and an explicit logic model.

A wide range of interventions was identified, including traditional solutions such as professional interpreter services and cultural competency training, as well as newer developments in AI-assisted communication. Professional interpreters have been shown to reduce diagnostic errors and improve satisfaction among LEP patients [14,15,103,272]. However, in the absence of formal services, reliance on multilingual staff is often viewed internally as a “gift” to colleagues and families rather than a systemic solution, highlighting a gap in sustainable support [51,62]. Additionally, empathy and stigma-reduction training improve mental health engagement [63,288,289]. The emergence of AI has also created innovations with the rise of AI-powered chatbots and multilingual tools that have shown promise for triaging and supporting routine patient interactions [208,235]. However, many of these tools still lack contextual awareness or real-time adaptability. This limits their effectiveness in complex encounters [206,277]. The overall results of this review highlight the need to study the interplay between various barriers to better understand the impacts and to properly mitigate those aforementioned impacts.

Communication barriers in health care rarely operate in isolation. Instead, linguistic, cultural, psychological, and cognitive barriers often interact in complex ways, compounding their effects on patient outcomes [161,175]. For example, a language barrier may initially prevent accurate expression of symptoms, but this can be exacerbated when the patient also experiences psychological discomfort, such as anxiety, stigma, or fear of judgment [69]. This compounding effect is clear in critical care settings. During the COVID-19 pandemic, physical communication challenges increased psychological distress. This created a cycle of frustration and fear that harmed recovery. This leads to further reluctance to engage with providers [15,32]. Even with interpreter services, MMDs may persist when patients conceptualize illness or treatment through culturally grounded frameworks that diverge from biomedical reasoning [33,52,260]. Studies show that this often leads to a deep feeling of “powerlessness.” Patients feel unable to handle both the language barrier and the cultural hierarchy of the hospital environment [69]. This interplay of barriers contributes to misdiagnosis, reduced treatment adherence, emotional distress, and, ultimately, a breakdown of trust in the patient-provider relationship [166].

Interventions must be designed with this interconnectedness in mind. While professional interpreters are effective in addressing language gaps, their impact improves significantly when coupled with cultural competency training that enables providers to recognize patients’ sociocultural beliefs and adapt communication accordingly [61,282]. Empathy training also plays a critical role by addressing both psychological safety and cognitive attunement, helping providers to better navigate emotional sensitivities and differing expectations [103,166,220]. In parallel, the use of plain language and visual aids has shown promise in bridging both linguistic and cognitive gaps, especially among patients with limited health literacy or those unfamiliar with medical reasoning [70,144,251]. For example, using low-tech strategies such as simple communication boards and video interpretation was crucial for overcoming various barriers during the pandemic [75].

Ultimately, the effectiveness of any single intervention is contingent on its ecological fit. That is to say, how well it aligns with and addresses the interdependent nature of barriers present in each clinical encounter. Integrated, multilevel strategies, which combine human-centered training, language access tools, and communication aids, are more likely to produce sustained improvements in trust, satisfaction, and clinical outcomes.

We map together repeated evidence into a transparent chain that explains how communication failures spread from minor interaction breakdowns to clinical and experiential harms. Multimedia Appendix 3 [33,36,46-48,51,58-60,64-67,69-72,84-87,91,105,106,108,135-137,143,144,154-160,164-169,172-174,176,178-182,186-188,194,200,207,214,215,217,224-227,236-239,244,249] explains it in more detail.

First, language barriers often lead to a loss of accurate information. For patients with LEP who lack interpreter support, this can lead to failures to express symptoms or to understand clinical instructions. This results in misdiagnoses, medical errors, and missed warning signs, as shown in studies on language mismatch and LEP [46-48,58,59,65-67,70-72,104,143,144]. When communication depends on ad hoc interpreters, the issue shifts from no translation to filtering. This filtering, often carried out by family members without medical vocabulary, can result in key symptoms being omitted and violations of confidentiality [64,154-160,164-169]. Together, these issues illustrate why language differences are often linked to serious safety problems. The clinical record is based on incomplete, distorted, or socially filtered information. Second, cultural barriers mainly affect interactions by creating mismatches in meaning and undermining relationships. Belief-system conflict directly leads to conflicts between cultural or religious norms and biomedical guidance. This conflict is linked to nonadherence and resistance to care [106,144,172-174,188,200]. Nonverbal misinterpretation is the second mechanism. Different interpretations of tone, gesture, or other signals can create feelings of disrespect, which heightens resistance to care [85,91,143,178,179,194]. Lastly, conflicts over authority and disclosure norms lead to a sense of disrespect and disregard for family hierarchy. This can result in feelings of powerlessness and perceptions of racism [69,86,87,180-182,186,187]. This pathway clarifies that cultural barriers go beyond simple preference differences. They can disrupt the social conditions needed for effective communication and acceptance of recommendations.

Third, psychological barriers work by hindering disclosure and disrupting narrative clarity when individuals feel emotionally threatened. Stigma is clearly linked to fear of judgment and to hiding relevant history, leading to the withholding of sensitive information [60,84,176,187,214,215,217]. Emotional overload and discomfort, such as distress, fear, anxiety, and low confidence, relate to fragmented or incomplete information. This can directly lower the quality of clinical judgment and triage [51,108,224-226]. Psychological safety also serves as a factor that anticipates dismissal or intimidation, leading to withdrawal from interaction [86,143,186,227-229]. Overall, these findings highlight a mechanism-focused view: emotional and social threats limit what patients can or will share, thereby affecting the content and completeness of the clinical information available for decision-making. Finally, MMDs lead to adverse outcomes through mismatched reasoning, assumptions, and expectations about time. A reasoning gap is the difference between how the general public understands a situation and how clinical diagnostics work [143,227,236-239]. This gap can cause decision-making paralysis and communication issues. Assumption divergence, or differing preconceived ideas about illness and responsibilities, is linked to patients feeling that their provider does not care [168,237-239,244]. Expectation gaps, especially conflicts between patients seeking a cure and clinicians focused on management, lead to frustration and reinforce the perception that providers lack compassion [33,36,194,207,249]. This explains why dissatisfaction and disengagement can continue even when people seem to understand what is being said. Thus, the main issue is not the words themselves, but the alignment between explanations and goals.

In summary, the reviewed evidence is combined into a connected mechanism-outcome framework. It shows that communication barriers are not just isolated inconveniences. They are systematic disruptions that influence what information is shared, how it is understood, and whether clinical relationships can support shared decision-making.

The findings of this review have several important implications for policy that extend beyond individual clinical encounters. They highlight the need for broader changes in health care systems. First, the strong and ongoing impact of language barriers shows we need language-access policies to ensure professional interpreters are available [51,60,69,109]. These policies should also regulate the use of AI translation tools to maintain accuracy and safety [57,100-102]. Second, the identified cultural and psychological barriers point to the importance of developing the workforce. Policies should include long-term programs in cultural humility, empathy training, and communication skills as part of clinician licensing and ongoing education requirements [50,69,135,202]. Third, the evidence about different mental models indicates a need for policies that encourage the creation and use of plain-language materials, visual aids for decision-making, and communication standards that are sensitive to health literacy in all care settings [55,62,70,76,122]. Finally, with the rise of AI, policymakers should back regulations that encourage responsible innovation and tackle equity issues [57,277,278]. They should demand more transparency in the model training and development process. AI models should be regularly checked for bias, and human oversight should be ensured. Together, these policy directions can lead to more fair, safe, and effective communication practices, helping to reduce the systemic disparities noted in this review.