Daytime sleepiness is a condition characterized by a persistent and overwhelming urge to sleep during the daytime, even in situations where it is inappropriate or inconvenient. It often develops as a symptom of underlying sleep disorders or other chronic ailments. Daytime sleepiness can significantly interfere with a person’s ability to stay awake, alert, and attentive during the day, thus raising safety concerns that also impact quality of life. Here are the common causes and known triggers:

Inadequate sleep
The most common and obvious reason is not getting enough sleep at night. Adults typically need 7-9 hours of sleep for optimal rest, allowing the brain and body to recover. Many people develop insomnia, a condition that triggers difficulty falling asleep or staying asleep, which can result in sleep deprivation and daytime sleepiness. Chronic sleep deprivation leads to the development of excessive daytime sleepiness.

Sleep disorders
Several sleep disorders can disrupt nighttime sleep and lead to daytime sleepiness. Sleep apnea, for example, is a condition that triggers intermittent breathing, causing oxygen deprivation during sleep, leading to fragmented sleep and daytime fatigue. Even Narcolepsy, a neurological disorder, is characterized by excessive daytime sleepiness, sudden muscle weakness (cataplexy), and vivid hallucinations during sleep onset.

Other disorders
The body’s natural clock, referred to as the circadian rhythm, regulates sleep-wake cycles. Changes in work timings, following an erratic work shift, irregular sleep schedules, or conditions like jet lag can disrupt this rhythm, leading to daytime sleepiness. Some people also deal with an irresistible urge to move their legs, triggered by a condition called restless leg syndrome (RLS). This is often accompanied by uncomfortable sensations, which can disrupt sleep.

Chronic ailments
Certain health complications trigger sleep disturbances, resulting in daytime sleepiness. These include chronic fatigue syndrome (CFS), a condition characterized by persistent, unexplained fatigue that does not improve with rest. Many people also develop emotional disorders like depression and anxiety, which can disrupt sleep patterns and lead to daytime fatigue. Even certain prescriptions given to manage chronic symptoms and discomforts affect the central nervous system, triggering drowsiness as a side effect.

Stress and lifestyle choices
High or chronic stress levels can make it difficult to fall asleep at night, leading to daytime fatigue. Further, poor nutrition, lack of physical activity, a sedentary lifestyle, and excessive caffeine intake can all contribute to daytime sleepiness.