prodromo

Prodromo, in medical usage, refers to early signs and symptoms that precede the onset of a disease or condition. The term derives from the Greek prodromos, meaning forerunner or prelude. Prodromal signs may be nonspecific, such as fatigue, malaise, irritability, or loss of appetite, or they may be more disease-specific, appearing hours to days before the full clinical picture.

In practice, a prodrome marks the transition from a preclinical or asymptomatic state to the initial symptoms of illness. Examples include a febrile prelude to infectious diseases like measles, where fever and upper respiratory symptoms appear before the rash; a migraine prodrome that includes yawning, fatigue, or mood changes before the headache; and in psychiatry, prodromal symptoms that precede disorders such as schizophrenia, often involving social withdrawal or functional decline. Epilepsy may involve an aura that functions as a prodromal indicator of a seizure.

Clinical significance lies in the potential for earlier diagnosis, risk stratification, and timely management or preventive measures. However, prodromes are not universally present and can be nonspecific or highly variable between individuals and conditions, so they are not diagnostic on their own. The concept emphasizes early detection and monitoring, with the prodromal period sometimes guiding patient counseling and clinical decisions.

See also: prodromal phase, early signs, premonitory signs.