Hypnic Headache, is a rare primary headache disorder that
is characterised by strictly sleep-related headache attacks.

Mainly elderly patients are affected, but younger patients
and even children might also suffer HH. Headache attacks
usually last between 15 and 180 minutes, but some patients
report headache attacks up to 10 hours. Almost all patients
report motor activity during headache attacks. Cerebral
MRI and 24-hour blood pressure monitoring should be
performed in the diagnostic work-up of HH. Other primary
headache disorders such as migraine and cluster headache
may also present with sleep-related headache attacks
and should be considered first. Caffeine taken as a cup
of strong coffee seems to be the best acute and
prophxlactic treatment option.