Underdiagnostik

Underdiagnostik, or underdiagnosis, is the failure to identify a disease or condition that is present in an individual or population. It results when a condition goes unrecognized by clinicians or is not recorded in health data, leading to delays or absence of treatment and to an underestimation of the true disease burden in surveillance systems.

Causes include limited access to care, screening gaps, asymptomatic or nonspecific presentations, cognitive biases among providers, and diagnostic uncertainty. System-level factors such as resource constraints, fragmented care, and inequities in health services also contribute. Data-related issues such as misclassification or incomplete medical records can mask true prevalence.

Common domains include chronic diseases (hypertension, diabetes), mental health conditions, infectious diseases in low-resource settings, and cancers diagnosed at later stages. The phenomenon can disproportionately affect vulnerable groups, contributing to health disparities.

Consequences include worse outcomes due to late treatment, higher mortality or disability, and distorted epidemiological estimates that hinder policy and resource allocation. It is distinct from underreporting and from overdiagnosis; underdiagnosis refers to missed recognition, underreporting to incomplete data submission, and overdiagnosis to identifying conditions that would not cause harm.

Strategies to reduce underdiagnosis include expanding access to primary care and screening, adopting standardized diagnostic criteria, improving clinician training, using decision-support tools, and leveraging population health data to identify at‑risk individuals for targeted assessment.

Addressing underdiagnostik requires measures across clinical practice, health systems, and data infrastructure to ensure accurate identification and appropriate care.