What Is Hypnic Headache?
It is a form of headache that is usually mistaken for migraine and cluster headaches. Unfortunately, most health practitioners do not think of this form of headache and they often miss to include this in their differential diagnosis.
This headache is benign and typically starts few hours after falling asleep and tends to wake up the person. This is why it is also known as "alarm clock headache". The headaches usually last 15 to 90 minutes and it may last up to 3 hours after waking. The pain is mild to moderate and generalized. However, it could be in one side of the head and even throbbing.
Hypnic headaches affect women more than men and often begin after age 50 years, but it may be seen in younger people as well. The episodes of headaches can repeat up to three times through the night for 7 to 10 nights in a month. Nausea, photophobia and phonophobia are usually absent in this form of headache. Surprisingly, daytime naps may aggravate the headache.