Understanding Headache

Headache is one of the commonest problems why patients seek medical attention. The cause of headache is very difficult to find in many cases and it makes it difficult to treat. Diagnosis and treatment of headache is based on careful clinical examination (including careful history, and physical examination) that is augmented by an understanding of the anatomy, physiology, and pharmacology of the nervous system pathways that mediate the various types of headaches.

The International Headache Society classifies headache as primary headache and secondary headache. Primary headaches are those in which headache and its associated features are the disorder in itself and not due to another disease. Secondary headaches are those caused by some other disease (pathology is somewhere else).

Primary headache can cause serious disability for a patient and decrease the quality of life significantly, whereas secondary headaches (like that seen in association with upper respiratory tract infections, which is common but rarely worrisome) are generally mild and do not cause severe disability and reduction in quality of life. Life-threatening headache is uncommon but should be kept in mind and vigilance is required in order to recognize and appropriately treat these patients.

Common causes of primary headaches are tension type headache (69%), migraine headache (16%), due to exercise (01%), cluster headache (0.1%), idiopathic stabbing headache (approximately 02%) and remaining the cause of headache can not be identified or idiopathic. The common causes of secondary headaches are systemic infection (63%) (including URTI upper respiratory tract infections, meningitis, encephalitis etc.), diseases of the eye like glaucoma, head injury (04%), diseases of blood vessels (01%), sub-arachnoid hemorrhage (less than 01%), brain tumor (0.1%) and remaining the cause of secondary headache can not be identified (called idiopathic).