Your thyroid is a small butterfly-shaped gland in your neck.  It makes hormones that control many important body functions, such as energy use, growth, heart rate, weight, digestion, and mood.  An underactive thyroid, also known as hypothyroidism, happens when your thyroid doesn't produce enough hormones. It affects about 10 million Americans, and women are more likely to have the condition than men.

What Are the Signs?

If you have an underactive thyroid, you might:

• Feel very tired all the time
• Gain weight, even if you're not eating more
• Feel cold when others are comfortable
• Have trouble thinking clearly or feel down
• Sleep more than usual
• Have a slower heartbeat
• Get constipated
• Notice changes in your period (for women)
• Have achy muscles and joints
• See changes in your skin, hair, or nails

What Causes It?

In the United States, the most common cause is when the body's defense system mistakenly attacks the thyroid. Worldwide, not getting enough iodine in the diet is the main cause, but this is rare in the U.S. because iodine is added to salt.

Other causes include:

• Having your thyroid removed surgically.
• Previous radiation treatment to the neck.
• Some medications like lithium or amiodarone.
• Pregnancy (usually temporary).

How Is It Diagnosed and Treated?

A simple blood test can measure thyroid hormone levels. If these levels are low, it means that the thyroid is underactive.

If you have an underactive thyroid, you may need to take a medicine called Levothyroxine. This medicine replaces the hormone your thyroid isn't making enough of.

Taking thyroid medication requires a bit of care. It's best to take it on an empty stomach, about an hour before breakfast or your morning coffee. Some foods, supplements (like calcium and iron), and certain stomach medications can interfere with how well your body absorbs the medicine, so it's important to space these out by at least four hours.

Not everyone with a slightly underactive thyroid needs treatment right away. Your doctor might recommend starting medication if you're experiencing symptoms, if you're pregnant or planning to become pregnant, or if you're under 30 years old.

As with any health condition, it's crucial to have open conversations with your healthcare provider about your symptoms, concerns, and treatment options. Living with an underactive thyroid is manageable with proper care and treatment. By understanding your condition and working closely with your doctor, you can keep your thyroid functioning well and maintain your overall health and well-being.

Karla Cano, MD, is accepting patients at White River Health Internal Medicine. To schedule an appointment, call 870-262-1510.