What causes insomnia?

According to Mayo Clinic, common causes of insomnia are stress, anxiety, depression, medical conditions, change in environment or work schedule, poor sleep habits, medications, caffeine and eating too late in the evening. Mayo Clinic notes that age also contributes to insomnia.

Insomnia caused by aging is attributed to a change in sleep patterns, a change in activity, a change in health, or medications. Risk factors for developing insomnia include being a woman, being older than 60 years old, a mental health disorder, being under stress, working the night shift and traveling long distances. A full medical assessment by a doctor can help determine why a person is suffering from insomnia.