LaVon Jackson, age 12, of Denton, Texas, for her question:

WHY DO SOME PEOPLE SUFFER FROM INSOMNIA?

Insomnia is the inability to sleep naturally. Doctors say there are many different reasons why people suffer with insomnia including indigestion or overexcitement.

Pain or discomfort from a physical illness will also sometimes interfere with sleep and cause

insomnia. So will coffee or other stimulants to the nervous system as well as some drugs that affect the brain.

Nonmedical people often speak of insomnia as though it were an illness in itself. Doctors, however, know that insomnia is a symptom or sign of an illness.

Sometimes insomnia is caused by psychological factors. It is often obviously related to conscious fears and worries, as for example when sleep is disturbed by frightening dreams. Everyone has occasional insomnia of this sort.

Insomnia may also be a symptom of either mild or severe mental illness.