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HYPOTHYROIDISM - THYROID UNDERACTIVE - MYXODOEMA

What is Hypothyroidism ?

The thyroid gland is found low in the neck and is shaped like a butterfly. It makes two hormones, thyroxine (T4) and triiodothyronine (T3), which are released into the blood circulation. These hormones control the speed of all the body's functions (or metabolism). In hypothyroidism (hypo = underactive, thyroidism = thyroid activity) the output of these hormones is reduced. The resulting decrease in metabolism produces various symptoms. General muscle slow-down leads to tiredness. Reduced body metabolism causes dry skin, hair loss, constipation and weight gain. Joints can swell up, and shortage of breath may develop due to effects on the heart. In women, periods may become heavy. Slower brain activity results in memory loss and poor concentration. Youngsters may fail to grow and may not do well at school. Some people have no symptoms at all, but the doctor may notice only a slow pulse or other minor change in appearance. If the thyroid gland is enlarged, the doctor may then call the condition Hashimoto's disease, after the Japanese physician who first described this combination of abnormalities.

How does Hypothyroidism occur ?

The body sometimes produces substances called antibodies. These are defence chemicals which are usually made only to deal with foreign substances (like viruses, other germs and things like pollen). In hypothyroidism, the antibodies (and the cells that make them) are directed against the body's own cells (in this case the thyroid). This is called auto-immune destruction, and is almost impossible to prevent or reverse. Once thyroid cell damage occurs in this way, it is usually permanent.

Why does Hypothyroidism occur ?

A tendency to develop auto-immune thyroid disorders is often inherited. Some people develop an underactive thyroid following an overactive thyroid condition earlier in life. . About one person in l00 develops this quite common condition. Both thyroid operations and the use of radioactive iodine for an overactive thyroid often result in an underactive thyroid state. Sometimes, certain foods and medicines (especially containing iodine) can cause it A particular type of underactive thyroid occurs 4 to 6 months after childbirth, in approximately one in 15 pregnancies. This so-called post-partum thyroiditis may cause either temporary or permanent thyroid underactivity, sometime preceded by a temporary overactive state.

Treatment Involved for Hypothyroidism

Tablets of synthetic thyroxine (T4) are the usual treatment, taken once daily. If you forget a dose once in a while no harm will result. The body can make all the triiodothyronine (T3) which it needs from this T4, and it does not need to be given separately in most cases. However, because T3 works more rapidly, in some situations your doctor may decide to commence your treatment using T3 out of preference. Thyroid extract is no longer recommended. Although it contains a mixture of T4 and T3, the content is not very consistent. Giving mixtures of T4 and T3 at the same time has also not been shown to have any advantages. Thyroxine is often started in a dose as low as 25 micrograms a day (or even lower in some people). The dose is gradually built up every month or two to give the body a chance to adjust. The doctor will use a regular examination, a blood test, and perhaps a heart examination (electrocardiograph) to decide about the final thyroxine dose, which is usually between 50 to 200 micrograms a day (0.05 to 0.2 milligrams). Always check the strength of thyroid tablets each time they are dispensed: mistakes can happen.

During Treatment for Hypothyroidism

Some improvement usually occurs within 2 weeks of starting treatment. It takes 4 to 6 weeks of daily tablets to get the full benefit of a particular dose. The older you are, the longer the doctor will take to build up the dose. Most symptoms will improve, but occasionally chest pain or shortness of breath develops, in which case the doctor needs to know straight away. If your underactive thyroid was picked up by chance in a screening test, you may not feel much better on treatment. It would be unwise to stop for this reason, since you were probably lucky enough to have your condition diagnosed before the more serious symptoms developed. If the thyroid gland was enlarged before treatment, it may get much smaller after treatment. If too much thyroxine is taken, palpitations, trembling and sweating may occur. Even without these symptoms, mild overdosage over several years may weaken the bones. This makes them more likely to be painful and to fracture. With the sensitive tests now available, it is possible for the doctor to be absolutely certain whether the dose being taken is correct or not.

After Treatment for Hypothyroidism

Once started, the need for thyroid tablet treatment continues lifelong. Treatment should never be stopped unless actually instructed by a doctor. It is a good idea to have a check-up and a thyroid blood test check once a year. If you very occasionally forget a dose, there is no need to take an extra dose the next day. As you get older, the dose may need to be increased or occasionally reduced to keep yourself healthy.

If Hypothyroidism is Left Untreated

Without treatment, hypothyroidism results in more and more fatigue, slowness of thought or depression, weight gain, and even heart failure. Temperature control may be lost, especially in elderly people. Then hypothermia (extremely low body temperature) may lead to coma. In a few instances, severe restriction of iodine in the diet has been shown to reverse the underactive thyroid. However, this is an unpredictable form of treatment and is not recommended in most cases.

Effects on Family of Hypothyroidism

Family and friends will often be surprised and pleased by the changes in your health and appearance. Because it is often inherited and more common in women, the doctor may suggest that particularly female relations (sisters, mother and children) should have a thyroid blood test check: one of them may even have an overactive thyroid, which sometimes occurs within the same family. Once thyroid tablets are started never stop them unless the doctor tells you to.