HEATHER, athlete and personal trainer: The thyroid is the largest gland in the neck and is responsible for regulating your body’s metabolism and energy levels. The three most common thyroid problems are underactive thyroid (hypothyroidism), overactive thyroid (hyperthyroidism) and thyroid nodules.

Symptoms vary with each condition. But people who suffer from hypothyroidism often feel cold and lack energy. Other symptoms include, but aren’t limited to: weight gain, slowed thinking and depression. People afflicted with hyperthyroidism often feel hot and have lots of energy. Other signs of the disease include weight loss, irritability and exhaustion.

Both diseases often are misdiagnosed as chronic fatigue syndrome, fibromyalgia or depression because their symptoms mirror those of other disorders.

However, if you are diagnosed with a thyroid problem, find a practitioner who will work with you. Incorporate exercise into your thyroid treatment plan to help increase your metabolism and energy levels and to assist in regulating your insulin levels.

It is extremely difficult for the average healthy individual to begin and maintain an exercise program.

As a thyroid patient, it is even more critical for you to utilize exercise to improve your health. Begin by finding an exercise activity that interest you such as walking, dancing or yoga. As always, I advocate the benefits of strength training as well.

My clients with thyroid disease have seen incredible results with weight loss, increased muscle tone and increased energy levels.

However, as you embark on your new exercise program, realize that whatever modality you choose, you are going to feel fatigued at first. You must take gradual steps in increasing your exercise, intensity and frequency. An exercise professional can help develop a program that best fits your needs, experience and current treatment protocols from your physician.

Most important, stay abreast of the latest research. The field of endocrinology is one of the least understood and finding a good physician who specializes in this area can be challenging - even in a big city like Philadelphia.

Finally, if you feel that this subject does not affect you, be aware that a recently released study by the American Association of Clinical Endocrinologists’ concluded that millions of Americans, once considered to have normal thyroids, should be tested and possibly treated for abnormal thyroid function. The AACE’s guidelines double the number of people who have abnormal thyroid function, bringing the total to 27 million - roughly the number of people with diabetes and cancer combined.

So, if you’re experiencing signs of a thyroid problem, get yourself checked.

Here are some area doctors who specialize in endocrinology and may be of help: