Thyroid Disease

WHAT IS IT?

Your thyroid is a butterfly-shaped gland in your neck, located just above your collarbone. It’s one of your endocrine glands, which make hormones. Thyroid problems include an overactive thyroid gland, an underactive thyroid gland and thyroid nodules.

Overactive thyroid (hyperthyroidism)

In this condition, your thyroid gland produces too much of the hormone thyroxine. Hyperthyroidism canaccelerate your body’s metabolism, causing a variety of signs and symptoms, including:

• Sudden weight loss
• Rapid or irregular heartbeat or pounding heart (palpitations)
• Increased appetite
• Nervousness, anxiety, and irritability
• Tremor, usually in the hands and fingers
• Sweating
• Changes in menstrual patterns
• Increased sensitivity to heat
• Changes in bowel patterns
• An enlarged thyroid gland (goiter)
• Fatigue, muscle weakness
• Difficulty sleeping
• Skin thinning
• Fine, brittle hair

Treatment.

Several treatments may be used, including:

• Radioactive iodine. Taken by mouth, radioactive iodine is absorbed by your thyroid gland, slowly destroying thyroid tissue. Thyroid hormone release is decreased, and symptoms usually resolve within three to six months. This treatment may cause the thyroid to become underactive (hypothyroidism). Eventually, you may need to take daily medication to replace thyroxine.
• Anti-thyroid medications. They prevent your thyroid gland from producing excess amounts of hormones. Symptoms usually begin to improve in six to 12 weeks, but treatment typically continues at least a year and often longer. For some people, the medications clear up the problem permanently, while others experience a relapse. 
• Beta-blockers. They won’t reduce your thyroid levels, but they can reduce signs and symptoms, such as a rapid heart rate and palpitations. Your doctor may prescribe a beta-blocker to help you feel better until your thyroid levels are closer to normal.
• Surgery. If you’re pregnant or can’t tolerate anti-thyroid drugs and you don’t want to or can’t have radioactive iodine therapy, thyroid surgery may be an option. A surgeon removes most of your thyroid gland. Risks of this surgery include damage to your vocal cords and parathyroid glands.

Underactive thyroid (hypothyroidism)

In this condition, your thyroid gland doesn’t produce enough thyroid hormone. Hypothyroidism upsets the normal balance of chemical reactions in your body. The signs and symptoms of hypothyroidism vary, depending on the severity of the hormone deficiency. At first, you may barely notice the symptoms, but as your metabolism continues to slow, you may develop more obvious signs and symptoms, including:

• Fatigue
• Increased sensitivity to cold
• Constipation
• Dry skin
• Weight gain
• Puffy face
• Hoarseness
• Muscle weakness
• Elevated blood cholesterol level
• Muscle aches, tenderness and stiffness
• Pain, stiffness or swelling in your joints
• Heavier than normal or irregular menstrual periods
• Thinning hair
• Slowed heart rate
• Depression
• Impaired memory

Treatment.

Standard treatment for hypothyroidism involves daily use of the synthetic thyroid hormone levothyroxine (Levoxyl, Synthroid, others) to restore adequate levels.

One to two weeks after starting treatment, you should notice that you’re less fatigued. The medication also gradually lowers cholesterol levels elevated by the disease and may reverse any weight gain. Treatment with levothyroxine is usually lifelong. Because the dosage you need may change, your doctor will likely conduct blood tests yearly to make sure your dosage is optimal.

If you have coronary artery disease or severe hypothyroidism, your doctor may start treatment with a smaller amount of medication and gradually increase the dosage. Progressive hormone replacement allows your heart to adjust to the increase in metabolism.

Certain medications, supplements, and even some foods may affect your ability to absorb levothyroxine. Talk to your doctor about the best time to take the medication if you eat large amounts of soy products, eat a high-fiber diet, or take other medications, such as iron supplements, cholestyramine, calcium supplements or aluminum hydroxide found in some antacids.

Thyroid nodules

Thyroid nodules are solid or fluid-filled lumps that form within your thyroid gland. The majority of thyroid nodules aren’t serious and don’t cause symptoms. Thyroid cancer accounts for only a small percentage of thyroid nodules.

Most people don’t know they have thyroid nodules until their doctors discover them during a routine medical exam. Some thyroid nodules, however, become so large that they can be felt or seen. Rarely, they may press on your windpipe or esophagus, causing shortness of breath or difficulty swallowing.

In some cases, thyroid nodules produce additional amounts of the hormone thyroxine. The extra thyroxine may cause signs and symptoms of hyperthyroidism, including weight loss, intolerance to heat, tremor and nervousness, and a rapid or irregular heartbeat.

A couple of different tests may be used to diagnose a thyroid nodule. In addition to blood tests, your doctor may recommend:

• Ultrasonography. This imaging technique uses high-frequency sound waves to produce images. It provides the best information about the shape and structure of nodules, and it may be used to distinguish cysts from solid nodules, to determine if multiple nodules are present, and as a guide in performing a fine-needle aspiration biopsy.
• Fine-needle aspiration biopsy. Nodules are often biopsied to make sure no cancer is present. Fine-needle aspiration biopsy helps to distinguish between benign and malignant thyroid nodules. During the procedure, your doctor inserts a very thin needle in the nodule and removes a sample of cells. The procedure takes about 20 minutes and has few risks. The samples are sent to a laboratory and analyzed under a microscope.

Treatment. For the vast majority of nodules that aren’t cancerous, treatment options include:

• Watchful waiting. Your doctor may suggest simply watching your thyroid nodule, which usually means a physical exam and thyroid function tests at regular intervals. If the benign thyroid nodule remains unchanged, you may never need treatment.
• Thyroid hormone suppression therapy. This involves treating a benign nodule with levothyroxine (Levoxyl, Synthroid, others), a synthetic form of thyroxine. The idea is that the additional thyroid hormone will signal the pituitary glands to produce less of the hormone that stimulates the growth of thyroid tissue. There’s no clear evidence the treatment consistently shrinks nodules or even that shrinking small, benign nodules is necessary.
• Surgery. Nodules that are so large they make it hard to breathe or swallow may be surgically removed. Surgery is also considered for people with nodules diagnosed as indeterminate or suspicious so that they can be examined for signs of cancer.

Treatment for a nodule that’s cancerous usually involves surgery. The usual treatment is the removal of the cancerous nodules, often along with the majority of thyroid tissue. Risks of thyroid surgery include damage to the nerve that controls your vocal cords (laryngeal nerve) and damage to your parathyroid glands. After surgery, you’ll need lifelong treatment with levothyroxine to supply your body with normal amounts of thyroid hormone.

Consult your doctor before taking any medications.

           Excerpt From: The Mayo Clinic. “Mayo Clinic A to Z Health Guide”.