Dieter Hitchcock, age 13, of Baton Rouge, La., for his question:
WHY DO SOME PEOPLE FEEL DIZZINESS?
Dizziness is a feeling of being faint, unsteady or lightheaded. What most people also describe as dizziness is what doctors call vertigo: a sensation of spinning, turning or failing in space, or of standing still while the objects around are moving.
Dizziness can be a normal physical reaction or it can be a sign of a disease. A person can feel dizziness and nausea at great heights, which can be a normal physical reaction. Or the dizziness could come from hardening of the arteries, or diabetes, to ear damage from infection or injury or from the use of drugs.
Many of the problems in the field of dizziness are still not well understood by medical experts. one reason is that the disease process is often concealed in the bones of the skull and is not easily accessible for study.
In general, however, doctors consider dizziness a relatively mild condition which may be caused by various parts of the body.
Vertigo, on the other hand, is a severe disturbance, usually accompanied by nausea and vomitting. It almost always orginates in the vestibular labyrinth the center for the sense of balance in the inner ear, in the auditory (hearing) nerve or in the vestibular nuclei, or nerve terminals, on the brain stem or their connections.
Sight also plays an important part in the body's sense of balance, and its loss or impairment is often part of the problem in a condition sometimes called multisensory dizziness. This disturbance usually occurs in persons who are elderly, or diabetic, or both. They may have cataracts or other eye disorders impairing their vision; they may have a lose of sensation from nerves which report the position of the muscles and tendons, thus contributing to the sense of balance.
Dizziness can also be a problem for people who hyperventilate, or breathe more than they need to.
When a person hyperventilates, the result is often a drop in the carbon dioxide in the blood, which causes constriction of the blood vessels in the brain. Hyperventilation is sometimes caused by a physical condition, but is often the result of an emotional disturbance, such as anxiety or worry over a physical disorder.
Still other people who say they feel dizzy are really feeling faint and may even lose consciousness. Symptoms of this kind often come from insufficient oxygen in the brain, because of disorders of the heart or blood vessels.
Faintness and dizziness may also be due to hypoglycemia, which is an abnormally low blood sugar level. This can occur in a diabetic who has taken too much insulin or too little food. More rarely it occurs in a person with a pancreatic tumor that causes overproduction of insulin.
Occasionally a person may lose his balance without any feeling of dizziness simply because his legs are unsteady.