Headaches can be<unk>  to many different<unk> s. Some of these include alcohol, NO, carbon monoxide poisoning, cocaine, caffeine and monosodium glutamate. Chronic use of certain medications used to treat headaches can also start causing headaches, known as medication overuse headaches. Headaches may also be a symptom of medication<unk> .
Headache attributed to a substance or its withdrawal
Sudden unexpected death in epilepsy
Acute behavioural disturbance
Recurrent brief depression
New daily persistent headache
Clinical descriptions of chronic fatigue syndrome
Sleeping disorders following traumatic brain injury
Long-term depression