Numerous factors can contribute to insomnia, including medical conditions, illnesses, allergies, medications, and lifestyle:
Mental health issues such as anxiety or depression. These are the most common causes of insomnia
Emotional distress caused by persistent feelings of grief, excessive worrying, anger, and stress.
Medical problems or illness. Many medical conditions and diseases can contribute to insomnia, including asthma, allergies, Parkinson’s disease, hyperthyroidism, acid reflux, kidney disease, and cancer. Chronic pain is also a very common cause of insomnia.
Prescription drugs can disrupt normal sleep cycles. Insomnia is associated with a variety of medications including stimulants used to treat ADHD, antidepressants, blood pressure medication, even over-the-counter drugs like cold or flu medications, and pain relievers (like Excedrin) that contain caffeine.
External stimuli including leaving the television on, sleeping with your computer on or loud noises (like street traffic).
Poor diet and lifestyle choices can also be contributing factors.
Other conditions such restless leg syndrome, circadian rhythm disruptions related to jet lag or late-night work shifts, or sleep apnea.