What is Headache?
One of the Most Common Symptoms Experienced by Humans.
Headache is one of the commonest symptoms experienced by humans. In fact, it is quite unusual not to have at least an occasional headache. Why some people never experience headache is not known.
It is probably linked with their inheritance of the chemical transmitters that pass messages in the brain from one nerve cell to another. The brain has a control mechanism for pain impulses and the transmitter substances involved in this also play a part in the emotions, As a general rule, happy people have fewer headaches than sad people but that is not the whole answer (Lance).
Headaches are usually harmless but can create concern about their origin. Very occasionally headaches are a pointer to a serious disease such as brain tumour or stroke. This is why many people seek advice from their doctors and, in some cases, are referred to specialist neurologists. Normally the severity of the headache bears no relation to the gravity of the diagnosis (Spira).
A great deal of research has been directed at determining the mechanisms responsible for the production of the pain of headache. While the brain is itself insensitive to pain, its covering membranes and its larger blood vessels are richly supplied by nerve fibres capable of transmitting the experience of pain. Most of the other structures within the head and upper neck, e.g., eyes, ears, nasal sinuses, skin, muscle, joints and arteries are also exquisitively pain sensitive (Spira).
This means that disorders in any of these structures may be experienced as a form of headache. The pain is produced through irritation of these structures via mechanical, chemical or inflammatory mechanisms and pain sensitive nerve fibres send a ‘pain’ message back to the brain. The brain can’t always tell where the pain message originated which is why it is sometimes difficult to pinpoint the exact cause of a headache (Spira).
Diagnosing headache involves differentiating between the most common forms of headache and those that may indicate an underlying illness. The types of headache can be categorised in various ways. One method is as follows:
- ‘Normal’ headaches such as goggle headache (excessive nerve stimulation), ice-cream headache, hot-dog headache (food reaction), Chinese restaurant syndrome (reaction to MSG), hangover, marijuana headache, fasting headache, rebound headache, exercise headaches, coital headaches, cough headache and mountain sickness.
- Recurring headaches include tension-type headache, migraine and cluster headache.
- ‘Nerve’ headaches ie produced by direct irritation or compression of the nerves supplying the head, face, or neck such as trigeminal neuralgia, glossopharyngeal neuralgia, neuralgia after shingles, atypical face pain, pain from the eye, sinusitis, head pain caused by teeth, temporomandibular joint dysfunction, and neck headache
- Muscle-contraction headaches.
- Medication-misuse headaches.
- Head injury headache
- Serious causes of headache such as hydrocephalus, sub-arachnoid haemorrhage, meningitis, encephalitis, brain tumour, cerebral oedema, high blood pressure, stroke, temporal arteritis and benign intracranial hypertension.
As there are so many types of headache and as headache affects each person differently, it is important that you consult your doctor.
Migraine and Other Headaches 2000 Professor James Lance
Headaches 2000 Dr Paul Spira Health Essentials
Understanding Migraine & Other Headaches 2002 Dr Anne MacGregor
Headache 1999 British Brain & Spine Foundation
Prepared by Louise Alexander, PhC, Grad Dip Comm Mngt, Former National Director of the Brain Foundation. Reviewed by Professor James Lance, AO, CBE, MD, Hon DSc, FRCP, FRACP, FAA, Consulting Neurologist, and author, “Migraine and Other Headaches”