Muscle contraction, vascular factors and infection are a few of many factors that can cause headaches.
A number of metabolic, toxic or environmental causes are:
- The most common cause of headache is scalp and neck "muscle contraction" or tension headache. This affects 20% of the population. Tension headaches are usually in relation to stress or anxiety.
- Vascular headaches, namely migraine and cluster headaches, make up the other large group of headaches – affecting 5 – 10% of the population.
Both tension and vascular headaches can occur in an individual at the same time. In practice, the distinction between these two entities is often less clear-cut, and there may be an element of both muscle tension and a vascular component at the same time.
- Headaches due to infection of surrounding structures: sinus infection, tonsillitis, toothache, meningitis.
- Headache due to inflammation of surrounding tissues: cervical spine arthritis, constant coughing, straining of the eyes, acute glaucoma, trigeminal neuralgia and temporal arteritis
- Certain conditions will cause a stretching or pulling of pain-sensitive parts and inner structures of the head. These include concussion and other head trauma, strokes, brain tumours and spinal taps (lumbar puncture).
If a headache is caused by a serious illness, other symptoms are often present, such as vomiting, dizziness or changes in vision.
- The use of certain medications (side-effects)
- Eating or drinking iced foods and fluids
- The use or withdrawal of alcohol ("hangover"), caffeine, or other analgesic drugs (analgesic headaches)
- Breathing in smoke or fumes from chemicals
- Repeated exposure to nitrate compounds (found in heart medicine and dynamite; also used in a meat preservative, sodium nitrate – such as in hot-dogs and bacon)
- Exposure to materials containing chemical solvents (for example benzene, turpentine, spray adhesives, rubber cement and certain inks)
- Eating foods (such as Chinese food) prepared with monosodium glutamate, a flavour enhancer
- Exposure to poisons such as insecticides, lead and carbon tetrachloride
- Use of drugs such as amphetamines
- High altitudes (above 4 500m)
- High blood sugar (hyperglycemia)
- Low blood sugar (hypoglycemia)
- Low calcium levels in the blood (hypocalcaemia)
- Kidney failure (uraemia)
Reviewed by Dr Andrew Rose-Innes, MD, Department of Neurology, Yale University School of Medicine, New Haven.
Body mirrors the mind