Which condition is characterized as a sleep disorder where individuals struggle to fall or stay asleep?

Insomnia is a condition specifically defined as a sleep disorder in which individuals have difficulty falling asleep, staying asleep, or waking up too early and being unable to return to sleep. This can lead to various symptoms, including fatigue, irritability, and difficulty concentrating during the day. The distinguishing factor of insomnia is the persistent nature of these sleep disturbances, which can be acute (short-term) or chronic (long-term). It often results from stress, anxiety, poor sleep habits, or medical conditions, making it highly relevant in discussions about sleep health.

In contrast, sleep apnea is characterized primarily by interruptions in breathing during sleep, leading to disrupted sleep patterns but not necessarily involving the same struggle to fall or stay asleep as insomnia. Narcolepsy involves sudden sleep attacks and excessive daytime sleepiness, leading to sleep episodes that are not directly related to difficulty initiating or maintaining sleep at night. Hypersomnia refers to excessive sleepiness during the day, which may not necessarily correlate with the inability to fall or stay asleep at night.

Understanding insomnia thus requires recognizing that it is specifically tied to challenges concerning sleep initiation and maintenance, which distinguishes it from other sleep disorders.