It's estimated that as many as 59 million Americans have a thyroid problem, but the majority don't know it yet. The thyroid, a butterfly-shaped gland located in the neck, is the master gland of metabolism. When your thyroid doesn't function, it can affect every aspect of your health, and in particular, weight, depression and energy levels.

Since undiagnosed thyroid problems can dramatically increase your risk of obesity, heart disease, depression, anxiety, hair loss, sexual dysfunction, infertility and a host of other symptoms and health problems, it's important that you don't go undiagnosed.

You don't need to have all of these symptoms in order to have a thyroid problem, but here are some of the most common signs that you may have a thyroid condition:

10. Muscle and Joint Pains, Carpal Tunnel/Tendonitis Problems.

Aches and pains in your muscles and joints, weakness in the arms and a tendency to develop carpal tunnel in the arms/hands, tarsal tunnel in the legs, and plantars fasciitis in the feet can all be symptoms of undiagnosed thyroid problems. (For more information)

9. Neck Discomfort/Enlargement.

A feeling of swelling in the neck, discomfort with turtlenecks or neckties, a hoarse voice or a visibly enlarged thyroid can all be signs of a "goiter" -- an enlarged thyroid gland that is a symptom of thyroid disease.

To help find out if your thyroid may be enlarged, try a simple "Thyroid Neck Check" test at home.

8. Hair/Skin Changes.

Hair and skin are particularly vulnerable to thyroid conditions, and in particular, hair loss is frequently associated with thyroid problems. With hypothyroidism, hair frequently becomes brittle, coarse and dry, while breaking off and falling out easily. Skin can become coarse, thick, dry,and scaly. In hypothyroidism, there is often an unusual loss of hair in the outer edge of the eyebrow. With hyperthyroidism, severe hair loss can also occur, and skin can become fragile and thin.

7. Bowel Problems.

Severe or long-term constipation is frequently associated with hypothyroidism, while diarrhea or irritable bowel syndrome (IBS) is associated with hyperthyroidism.

6. Menstrual Irregularities and Fertility Problems.

Heavier, more frequent and more painful periods are frequently associated with hypothyroidism, and shorter, lighter or infrequent menstruation can be associated with hyperthyroidism. Infertility can also be associated with undiagnosed thyroid conditions. (For More Information)