What is a common cause of secondary insomnia?

Secondary insomnia is characterized by difficulty sleeping that is a result of a specific underlying condition or factor. Medical conditions, such as chronic pain, respiratory disorders, or psychiatric disorders like depression and anxiety, can significantly impact a person's ability to achieve restful sleep. When insomnia is rooted in these medical issues, treating the primary condition is often essential for alleviating the sleep disturbances.

While stress, caffeine consumption, and an irregular sleep schedule can contribute to insomnia, they are generally considered primary causes of insomnia rather than secondary. Stress might lead to difficulty sleeping, but it doesn’t arise from an existing medical condition. Caffeine is a stimulant that can affect sleep patterns, but its effects are not due to a secondary issue. An irregular sleep schedule can disrupt the body's circadian rhythm, causing primary insomnia. Therefore, medical conditions are the most appropriate choice when identifying a common cause of secondary insomnia.