A<unk>  is a sudden and severe headache. Since it is sometimes a sign of a medical emergency, one should "seek immediate medical attention for any headache that comes on suddenly and severely." The name<unk> " signifies the intensity and acuity of such headaches.
Thunderclap headache
Tension headache
Rebound headache
Cluster headache
Red wine headache
Morning headache
Retinal migraine
Migraine