Millions of Americans want to lose weight and often rely on the help of "diet pills." Most of these pills contain a medicine called "Ephedra" which comes from a Chinese herb, Ma Huang. The principle active ingredient is ephedrine which has been used in the past to treat certain lung problems, but now is being promoted and used to aid weight loss and perhaps enhancing athletic performance.

Numerous complaints are surfacing concerning the dangers of ephedrine including heart palpitations, anxiety, insomnia, constipation and tremor. Now, complaints and lawsuits are appearing that accuse ephedrine of causing heart attacks, stroke, seizures and psychiatric illnesses.

What is ephedra? It is a substance that acts in many ways the same as amphetamines or "speed." It works on the autonomic nervous system which controls many functions in the body including blood vessel tone, heart rate and digestion. Ephedra can decrease appetite and in some people can help them lose weight. But the side effects can potentially be life-threatening. If the ephedrine is used improperly (taking too much), it can easily cause elevation of blood pressure to the level of potential stroke in some patients. Palpitations are common and life-threatening arrhythmias (heart rate and rhythm disturbance) can occur. Heart attacks are also potential end results of this potentially dangerous medicine.

Athletes, beware! Ephedrine causes constriction of blood vessels. With exercise these same blood vessels need to be dilated at the surface of the body to aid in perspiration and prevent overheating. Bingo. Overheating and stress on the heart could lead to death.

Sorry. It seems the best way to lose weight is to eat properly and increase exercise under the guidance of a medical professional. Maybe one day we'll find an easier way.

Dr. Robert Overholt has been in private practice for more than 30 years. He is the host of the television program "The Dr. Bob Show" airing weekly in 13 million homes on the Goodlife Television Network. If you have a question for Dr. Bob, write "The Dr. Bob Show" at 6700 Baum Drive, Suite 1, Knoxville, TN 37919 or send your e-mail to letters@drbobshow.com.