Insomnia is a sleep disorder characterized by difficulty falling asleep, staying asleep, or waking too early and being unable to return to sleep, resulting in impaired daytime functioning. It may be short-term (acute) due to stress, travel, illness, or environmental changes, or long-term (chronic), often associated with anxiety, depression, chronic pain, medication effects, or poor sleep habits. Symptoms can include fatigue, irritability, difficulty concentrating, mood disturbances, and reduced performance at work or school. Insomnia can affect overall physical and mental health when persistent, increasing the risk of cardiovascular problems and weakened immune function. Identifying underlying causes and patterns is essential for effective management and restoring healthy sleep.