What is Hypothyroidism?
Your thyroid is a butterfly-shaped gland located at the base of your neck, just below your Adam's apple. Although it weighs less than an ounce, the thyroid gland has an enormous effect on your health. All aspects of your metabolism, from the rate at which your heart beats to how quickly you burn calories, are regulated by thyroid hormones.
As long as your thyroid releases the proper amounts of these hormones, your system functions normally. But sometimes your thyroid doesn't produce enough hormones, upsetting the balance of chemical reactions in your body. This condition is known as hypothyroidism, or underactive thyroid disease.
Women, especially those older than 40, are more likely to have an underactive thyroid than men are. By age 60, as many as 17 percent of American women may have hypothyroidism. The condition seldom causes symptoms in the early stages, but over time, untreated hypothyroidism can cause a number of heath problems.
The good news is that thyroid function tests have improved considerably in recent years, and early diagnosis is easier. In addition, treatment with synthetic thyroid hormone is usually simple and effective once the proper dosage is established. Natural treatment options also exist.
Signs and symptoms of Hypothyroidism
The signs and symptoms of hypothyroidism vary widely, depending on the severity of the hormone deficiency. But in general, any problems you do have tend to develop slowly, often over a number of years.
At first, you may barely notice symptoms such as fatigue and sluggishness, or you may simply attribute them to getting older. But as your metabolism continues to slow, you may develop more obvious signs and symptoms, including:
- Increased sensitivity to cold.
- Pale, dry skin.
- A puffy face.
- Hoarse voice.
- An elevated blood cholesterol level.
- Unexplained weight gain. Many people attribute their
weight gain to an underactive thyroid, but this is true
only in a few cases. Hypothyroidism will rarely cause you
to gain more than 10 to 20 pounds â€” most of which is
- Muscle aches, tenderness and stiffness, especially in
your shoulders and hips.
- Pain and stiffness in your joints and swelling in your
knees or the small joints in your hands and feet.
- Muscle weakness, especially in your lower extremities.
- Heavier than normal menstrual periods.
When hypothyroidism isn't treated, symptoms can gradually become more severe. Constant stimulation of your thyroid to release more hormones may lead to an enlarged thyroid (goiter). In addition, you may become more forgetful, your thought processes may slow or you may feel depressed.
Advanced hypothyroidism, known as myxedema, is rare, but when it occurs it can be life-threatening. Symptoms include drowsiness and intense intolerance to cold followed by profound lethargy and unconsciousness. In some cases, myxedema can be fatal.
Hypothyroidism in children and teens
Although hypothyroidism most often affects middle-aged and older women, anyone can develop the condition, including infants and teenagers. Initially, babies born without a thyroid gland or with a gland that doesn't work properly may have few signs and symptoms. When newborns do have problems, they may include:
- Yellowing of the skin and whites of the eyes
(jaundice). In most cases, this occurs when a baby's liver
can't metabolize a molecule called bilirubin, which
normally forms when the body recycles old or damaged red
- Noisy breathing.
- A large, protruding tongue.
As the disease progresses, infants are likely to have trouble feeding and may fail to grow and develop normally. They may also have:
- Rough, dry skin
- Poor muscle tone
- Excessive sleepiness
Left untreated, even mild hypothyroidism in infants can lead to severe physical and mental retardation.
In general, children and teens who develop hypothyroidism have the same signs and symptoms as adults do, but they may also experience:
- Poor growth, resulting in short stature
- Delayed development of permanent teeth
- Delayed puberty
- Difficulty in school
Screening and diagnosing Hyperthyroidism
Because hypothyroidism is more prevalent in older women, some endocrinologists recommend that women age 60 and older be screened for the disorder during routine annual physical examinations. Some doctors also recommend that pregnant women be tested for hypothyroidism.
In general, your doctor may test for an underactive thyroid if you're feeling increasingly tired or sluggish, have dry skin, constipation and a hoarse voice, or have had previous thyroid problems or goiter.
Diagnosis of hypothyroidism is based on your symptoms and the results of blood tests that measure levels of TSH and sometimes the levels of the thyroid hormone thyroxine. Low levels of thyroxine and high levels of TSH indicate an underactive thyroid. That's because your pituitary produces more TSH in an effort to stimulate your thyroid gland into producing more thyroid hormone.
In the past, doctors weren't able to detect hypothyroidism until symptoms were fairly advanced. But by using the sensitive TSH test, doctors are able to diagnose thyroid disorders much earlier â€” often before you ever experience symptoms. Because the TSH test is the best screening test, your doctor will likely check TSH first and follow with a thyroid hormone test if needed. TSH tests also play an important role in managing hypothyroidism. They help your doctor determine the right dosage of medication, both initially and over time.
In addition, TSH tests are used to help diagnose a condition called subclinical hypothyroidism, which usually causes no outward signs or symptoms. In this condition, you have normal blood levels of T-3 and T-4, but higher than normal levels of TSH.
Standard treatment for an underactive thyroid involves daily use of the synthetic thyroid hormone levothyroxine (Levothroid, Synthroid). The oral medication restores adequate hormone levels, shifting your body back into normal gear.
Soon after starting treatment, you'll notice that you're feeling 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, but because the dosage you need may change, your doctor is likely to check your TSH level every year or so.
To determine the right dosage of levothyroxine initially, your doctor generally checks your level of TSH after two to three months. Excessive amounts of the hormone can accelerate bone loss, which may make osteoporosis worse or add to your risk of this disease.
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.
Levothyroxine causes virtually no side effects when used in the appropriate dose and is relatively inexpensive. If you change brands, let your doctor know to ensure you're still receiving the right dosage. Also, don't skip doses or stop taking the drug because you're feeling better. If you do, the symptoms of hypothyroidism will gradually return. People with hypothyroidism need to take medication for the rest of their lives.
Certain medications, supplements and even some foods may affect your ability to absorb levothyroxine. Talk to your doctor if you eat large amounts of soy products or a high-fiber diet or you take any of the following:
- Iron supplements
- Cholestyramine (Questran)
- Aluminum hydroxide, which is found in some antacids
- Sodium polystyrene sulfonate (Kayexalate)
If you have subclinical hypothyroidism, discuss treatment with your doctor. For a relatively low level of TSH, you probably won't benefit from thyroid hormone therapy, and treatment could even be harmful. On the other hand, for a higher TSH level, thyroid hormones may improve your cholesterol level, the pumping ability of your heart or your energy level