• Mental health disorders: anxiety disorders, such as post-traumatic stress disorder, may disrupt your sleep. Awakening too early can be a sign of depression. Insomnia often occurs with other mental health disorders as well.
• Medications: Many prescription drugs can interfere with sleep, such as certain antidepressants and medications for asthma or blood pressure. Many over-the-counter medications — such as some pain medications, allergy and cold medications, and weight-loss products — contain caffeine and other stimulants that can disrupt sleep.
• Medical conditions: Examples of conditions linked with insomnia include chronic pain, cancer, diabetes, heart disease, asthma, gastroesophageal reflux disease (GERD), overactive thyroid, Parkinson's disease and Alzheimer's disease.
• Sleep-related disorders: Sleep apnea causes you to stop breathing periodically throughout the night, interrupting your sleep. Restless legs syndrome causes unpleasant sensations in your legs and an almost irresistible desire to move them, which may prevent you from falling asleep.
• Caffeine, nicotine and alcohol: Coffee, tea, cola and other caffeinated drinks are stimulants. Drinking them in the late afternoon or evening can keep you from falling asleep at night. Nicotine in tobacco products is another stimulant that can interfere with sleep. Alcohol may help you fall asleep, but it prevents deeper stages of sleep and often causes awakening in the middle of the night.
Courtesy: Mayo Clinic
