The most common type is a tension, or stress-induced, headache brought on by computer work, low blood sugar, or a long work day. More serious headaches, such as cluster headaches or migraines, can occur regularly and without warning, and can be very debilitating.
Hypnic headaches, also called “Alarm Clock Headaches,” awake a person the same time each night during the time the person is dreaming (the REM cycle). The exact cause is unknown. The pain is usually felt on both sides of the head, and may be accompanied by nausea, or light and sound sensitivity.
Migraines and Clusters
Migraines are usually genetic and cause sharp, stabbing, pulsating pains on one side of the head. Cluster headaches, a type of migraine, affect one side of the head behind an eye. They often recur at the same time each day, waking a person up, and can last for hours.
A person who wakes up each morning with a headache may be suffering from sinus headaches. Sinus X-rays, along with a history and physical examination, can help diagnose a sinus headache. Antihistamines, air purifiers and the removal of allergens can often cure these headaches.
Many nighttime headaches are induced by chocolate, cheese, MSG, alcohol, smoking, and drug use. Keeping a dietary, habit, and headache diary may isolate factors that cause nighttime headaches.