Thyroid disorders are common in the United States. The thyroid gland produces hormones that regulate metabolism.
If your thyroid is overactive (hyperthyroidism), you might feel anxious or weak. You might experience tremors, palpitations, increased perspiration and weight loss despite normal or increased appetite. Hyperthyroidism also can cause increased heart rate or an abnormal heart rhythm (atrial fibrillation), osteoporosis, elevated calcium levels and shortness of breath.
You also might notice hyperactivity; abnormal stare (eyelid retraction) and lid lag; warm and moist skin; and thin, fine hair. Hyperthyroidism is diagnosed with a blood test showing a decreased level of thyroid-stimulating hormone, or TSH, and elevated free levels of thyroid hormones (T3 and T4).
Typically in nonpregnant patients, a radioactive iodine uptake scan is performed to verify the overactive thyroid gland. Once diagnosed, this condition is usually treated by a specialist with oral medication, radioiodine or surgery.
If your thyroid is underactive (hypothyroidism), you might feel tired and sluggish. You Might suffer cold intolerance, weight gain, constipation, dry skin, muscle aches and menstrual irregularities.
Hypothyroidism can cause decreased heart rate, elevated blood pressure and increased cholesterol levels. You might notice impaired memory and concentration and slowing of movement and speech, dry skin, hoarseness, swelling, puffiness in the face, loss of eyebrows, depression and joint pain. Hypothyroidism is five to eight times more common in women than men.
A physical exam might reveal enlargement of the thyroid gland (goiter) and delayed reflexes. Because the typical symptoms are nonspecific, the diagnosis of hypothyroidism relies heavily on laboratory tests. It is typically confirmed with blood tests showing an elevated level of TSH and decreased levels of free T4.
Once diagnosed, this condition is easily treated with levothyroxine, an oral medication that is a synthetic replacement for T4. When the right dose of medication is determined, TSH returns to normal and symptoms improve.
It is important that hypothyroidism be detected in any woman who wants to become or is pregnant because low thyroid hormone might decrease fertility or impair fetal brain development.
Also, it is important that thyroid function studies be monitored periodically to ensure the correct dose of levothyroxine. Dosage of this medication might change with weight gain, weight loss or pregnancy.
Therapy for hypothyroidism is almost always lifelong. Levothyroxine is safe and generally effective over many years. Patients with thyroid disorders can live long and healthy lives if adequately treated.
Dr Emily Furlow White is an internal medicine specialist with Baptist Health Medical Group Family Medicine London.