Headaches are one of the most common ailments affecting humans. Between 40 to 52% of the global population has had a significant headache at some point in time. The lifetime prevalence of headaches is estimated to 93% in men and 99% in women.
The scope of the problem is immense, illustrated by the fact that there are hundreds of national headache societies across countries and thousands of books on headaches. Headaches can vary from the mild, just a nuisance to be ignored, to life-threatening massive brain haemorrhages. The International Classification of Headache Disorders, lists over 300 distinct types including a specific headache attributable to space travel.
Types of headaches and when to worry
Several types of innocuous headaches can co-exist. It is important to quickly recognise a new, possibly dangerous headache, which could occur in 10% of all headaches. When symptoms and history are vague, so is the possibility of a precise diagnosis. Recognising the dangerous headache requires knowledge, clinical acumen and a high index of suspicion. Investigations today are so sophisticated that “incidentalomas” (masses or lesions found during imaging that were not the primary reason for imaging) are picked up on MRIs and even angiograms, which however, may not explain the headache itself. Clinical corelation is essential. An investigation presupposes that a narrow differential clinical diagnosis has been made.
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A “thunderclap explosive headache”, particularly at the back of the head, occurring within a minute or the “worst headache I’ve ever had” along with neck discomfort may suggest a brain haemorrhage. A new type of headache, one that has not been previously experienced – sudden, severe, with vomiting, drowsiness and visual disturbances – needs immediate investigations. It is better to go directly to an advanced neurosurgical centre rather than the nearest doctor in such cases.
One important fact to note is that headaches should not be attributed to co-existing hypertension. Only a hypertensive crisis with persistent diastolic blood pressure of over 120mm Hg may contribute to a headache.
A postural headache, increasing with bending and rolling over in bed or when having a bowel movement is significant. A headache with persistent intense vomiting or which wakes one from sleep could also be a dangerous headache.
Headaches could also precede a stroke – facial, arm weakness and speech difficulties must be looked for. Like aneurysms (weakness in the arterial wall), abnormal connections between arteries and veins in the brain (arteriovenous malformation ) can leak or rupture causing a severe headache. This has to be managed before a second, often fatal bleed, occurs. Brain tumours, brain infections, brain swelling, acute hydrocephalus (obstruction to the cerebrospinal fluid pathway) are also causes of dangerous headaches. A headache after a head injury and severe headaches with high fever also need to be investigated.
Headaches progressively increasing significantly over 24 hours, occurring for the first time in those over 50 years of age and in those with cancer need to be evaluated. A severe headache in the third trimester of pregnancy with elevated blood pressure could be a symptom of preeclampsia.
Evaluating a headache
A detailed drug history is essential in evaluating headaches. This should include use of blood thinners, steroids, oestrogens, contraceptives, immunosuppressants and chemotherapy. Hypo- or hyperglycaemia causing headaches must be reversed immediately
Never discount suggestions or associations given by the patient. A physical examination (general, ENT, ophthalmic, dental, neurologic) should be conducted. A psychometric evaluation may also be necessary. psychometric evaluation is important but often not diagnostic. Details regarding time of onset, frequency, type of pain, location, aggravating and reducing influences, severity and duration could give important clues.
A headache in the presence of congenital heart disease, ear discharge or other major septic focus, a headache following minor trauma particularly in the elderly, persistent headaches in young children and headaches with seizures could be dangerous headaches. Glaucoma and other eye conditions could present with severe pain over the eyes. Sinusitis produces a constant dull aching headache. Malaise, nasal discharge and local tenderness, headaches increasing with head jarring, bending and stooping can all aid in a diagnosis. In frontal sinusitis, pain is more in the early morning and in maxillary sinusitis, afternoon. Every headache should be considered organic: for example, diagnose a “muscle contraction” headache not a “tension” headache”. Sudden, severe, generalised headaches, in a drowsy patient looking ill, with fever, increased pulse rate , sweating, neck stiffness and with visual disturbances require urgent evaluation.
Reevaluate and revise
Any patient coming to an emergency room for headache management almost certainly does not have a psychosomatic headache. An appropriate investigation of a dangerous headache is mandatory. However tests should not be resorted to, without a detailed clinical history and examination. Response to analgesics and the long-standing presence of a known headache, does not exclude a new dangerous headache. Reevaluate, revise the diagnosis and seek a specialist’s opinion when in doubt. Headaches can rarely even be the sole manifestation of a seizure, picked up on a EEG, responding only to anti-convulsants.
Sometimes however, living with a non-serious headache may be better than trying to find a specific cause!
(Dr. K. Ganapathy is a distinguished professor at the Tamil Nadu Dr. MGR Medical University and past president of the Neurological Society of India and the Telemedicine Society of India. Email: drkganapathy@gmail.com)
