Obtaining and maintaining an aviation medical certificate requires meeting strict physical, psychological, and neurological standards established by civil aviation authorities. Medical conditions that frequently result in certification denial or disqualification include active cardiovascular diseases, uncontrolled hypertension, insulin-dependent diabetes, epilepsy or seizure disorders, severe psychological conditions such as psychosis or unmanaged depression, substance abuse history, and major uncorrected visual or auditory impairments. Aviation medical examiners review comprehensive health histories to ensure a pilot experiences no sudden incapacitation risks while operating aircraft in shared airspace.