The nervous system is composed of the brain and spinal cord, together known as the central nervous system, and a vast array of peripheral nerves that transmit information to and from these central structures. The nervous system may be damaged by infection, injury, vascular problems, inflammation, and degeneration. However, the causes of many general nervous system disorders are not fully understood.
The first article deals with pain, which is a common symptom of many disorders. A description of the pain often helps in the diagnosis of a disorder. Effective painkillers and treatments such as transcutaneous electrical nerve stimulation (TENS) mean that prolonged, severe pain can be effectively treated and/or controlled.
The different types of headache are discussed next. Tension headaches cause discomfort and pain to millions of people every year, often due to stress or tension. Migraine is also relatively common, while cluster headaches are a severe but less common type of headache that occur in a characteristic pattern. A headache can be a sign of an underlying disorder, and persistent or severe headaches associated with other symptoms, such as vomiting, should be assessed by a doctor without delay.
The final article in this section discusses chronic fatigue syndrome, a complex and debilitating condition.
Headaches and migraine in children are covered elsewhere (see Infancy and childhood).
For more information on the structure and function of the brain and spinal cord.
From the 2010 revision of the Complete Home Medical Guide © Dorling Kindersley Limited.
The subjects, conditions and treatments covered in this encyclopaedia are for information only and may not be covered by your insurance product should you make a claim.