drowsiness

Drowsiness is a state of increased sleep propensity or reduced alertness that impairs wakefulness and concentration. It can occur intermittently or persistently and may improve after sleep or worsen with further wakefulness.

Common causes include insufficient or disrupted sleep, and sleep disorders such as obstructive sleep apnea, narcolepsy, or hypersomnia. Medications with sedating effects (antihistamines, certain antidepressants, benzodiazepines), alcohol, and other substances can promote drowsiness. Medical conditions such as thyroid disorders, anemia, infections, diabetes, kidney or liver disease, and mental health disorders like depression or anxiety may contribute. Environmental factors (shift work, jet lag, nighttime noise or light) and dehydration or poor nutrition can also play a role.

Signs of drowsiness include frequent yawning, drooping eyelids, nodding off, slower thinking, reduced attention, and slower reaction times. It may be accompanied by headaches or nausea and should be distinguished from fatigue, which is a broader sense of low energy.

Evaluation typically involves a medical history review and medication check, sleep history or diary, and targeted tests (for example, thyroid function, blood counts, glucose). Sleep studies (polysomnography) or sleep latency testing may be used if a sleep disorder is suspected.

Management focuses on treating underlying causes, improving sleep hygiene, and minimizing safety risks. Practical steps include regular sleep schedules, limiting alcohol and sedatives, daytime naps when appropriate, and addressing medical or nutritional deficiencies. In some conditions, medical therapies or devices may be indicated and should be guided by a clinician. Seek medical advice if drowsiness is persistent, worsening, or associated with headache, confusion, weakness, or vision changes.