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A headache is a painful sensation in the muscles, the skin, or one of the organs in the head or near the brain.
What is going on in the body?
Causes of headaches commonly fall into four categories:
There are no nerve endings in the brain itself. Therefore, a headache is a painful sensation in the muscles, the skin, or one of the organs in the head or near the brain. The pain can be confined to a small area or it can cover the entire head.
- vascular headaches, which are caused by conditions affecting the blood vessels. A migraine is a common form of vascular headache.
- tension headaches, usually brought on by muscle tension
- inflammatory headaches, which are caused by infections or lesions such as tumours
- headaches associated with abnormalities of cranial nerves, or cranial neuralgias. The cranial nerves supply the face, head, and neck.
Some headaches are preceded by auras, which are sensations that things are not quite right. These auras can involve unusual sounds, smells or visions.
Most headaches are benign, which means they are self-limited and not likely to be serious. However, some headaches are serious and require extensive evaluation.
What are the signs and symptoms of the condition?
A headache may involve: What are the causes and risks of the condition?
Headaches have a wide variety of causes.
Vascular headaches include: Tension headaches are caused by stress or by abnormalities in the neck, muscles, or bones. They can also be caused by conversion disorders, which are psychological problems that cause symptoms similar to those accompanying an actual physical condition.
Inflammatory headaches are caused by:
Cranial neuralgias involve severe pains in or about the face or scalp, and are caused by abnormalities of the trigeminal or glossopharyngeal nerves. The trigeminal nerve controls sensation in the face, cheek, and jaw. The glossopharyngeal nerve controls the throat and vocal cords.
- lesions such as brain tumours
- meningitis, which is an infection or inflammation of tissue covering the brain and spinal cord
- bleeding into or around the brain, which occurs with a subdural haematoma, epidural haematoma, or subarachnoid haemorrhage
- autoimmune disorders, or diseases in which the body produces chemicals that attack its own tissues
- arteritis, which is an inflammation of the wall of an artery
What can be done to prevent the condition?
Many causes of headaches are not preventable. An individual may develop headaches after exposure to alcohol, caffeine, chocolate, or stress. Avoiding those triggers can help prevent headaches.
Medications that can help prevent migraine headaches include:
How is the condition diagnosed?
- beta-blockers, such as propranolol
- calcium channel blockers, such as verapamil
- tricyclic antidepressants, such as amitriptyline, and nortriptyline
- anticonvulsants, such as valproic acid and valproate
- methysergide maleate
The first step in diagnosing the cause of headaches is a complete history and physical examination. The doctor may then order tests, including:
What are the long-term effects of the condition?
- a cranial CT scan, or examination of the head with a special three-dimensional X-ray
- a cranial MRI, which is a special three-dimensional image made using a magnetic field
- an electroencephalogram or EEG, which is a recording of brain waves
- skull X-rays
- blood tests like an ESR
- a spinal tap, which involves removing a small amount of cerebrospinal fluid with a thin needle
- an electromyogram or EMG. This test is a recording of the electrical activity of selected muscle groups.
- biopsy of the arteries in the head. This test involves collecting a piece of the artery and examining it under the microscope.
- testing of levels of certain drugs or toxins in the blood
Most people do not have any significant long-term effects because their headaches are benign and recur infrequently. However, vascular headaches can result in significant loss of quality of life. An individual with a brain tumour, bleeding, or meningitis is at risk for severe illness and death.
What are the risks to others?
Headaches are not contagious and pose no risk to others. If the underlying cause of the headache is an infection such as meningitis, the infection may be highly contagious. Some headaches, such as migraines, tend to run in families.
What are the treatments for the condition?
Over-the-counter analgesics such as ibuprofen, paracetamol, or aspirin will relieve most headaches.
Medications for acute migraine attacks include:
What are the side effects of the treatments?
- nonsteroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen and naproxen
- triptans, such as sumatriptan or zolmitriptan
Over-the-counter analgesics may cause stomach upset and allergic reactions. Other side effects depend on the medication used. Calcium channel blockers, for example, are associated with a significantly increased risk of heart attack or congestive heart failure in individuals with high blood pressure.
What happens after treatment for the condition?
Complications of headaches are usually limited. However, some causes of headaches such as brain tumours, bleeding, or meningitis may cause significant complications.
How is the condition monitored?
A person with frequent or severe headaches may be asked to keep a headache diary. Any new or worsening symptoms should be reported to the doctor.
Author: James Broomfield, MD
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Potential conflict of interest information for reviewers available on request