Just below your Adam’s apple is a butterfly-shaped gland called the thyroid. The thyroid controls a wide variety of body functions.

Hypothyroidism—an underactive thyroid—is the most common thyroid disorder. A person with hypothyroidism might notice:

• Fatigue
• Forgetfulness
• Mood swings
• Weight gain
• A hoarse voice
• Trouble swallowing
• An inability to tolerate cold

On the other hand, your thyroid can become overactive. A person with hyperthyroidism might experience:

• Irritability or nervousness
• Muscle weakness
• Irregular menstrual periods
• Weight loss
• Trouble sleeping
• An enlarged thyroid (goiter)

All the symptoms of these conditions do not occur in each person. And, if you have a thyroid problem, you might not even be aware of it. Untreated thyroid disease can boost cholesterol levels, interfere with fertility, lead to osteoporosis, and even contribute to death from circulatory and cardiovascular disease.

Fortunately, a simple blood test can determine whether the thyroid is overactive or underactive.

Physicians may recommend screening for:

• Women who take hormone replacement therapy and still have persistent menopause symptoms
• Older people with fatigue or depression

The good news: Medication usually can correct an overactive or underactive thyroid. Talk with your physician if you have noticed any of the symptoms listed in this article.