Thyroid gland is an important endocrine gland in our body that produces hormones called, triiodothyronine (T3) and thyroxine (T4). These hormones are mainly responsible for regulation of lipid and carbohydrate metabolism. They are also necessary for the growth and development of children.
Thus any condition that causes either overproduction or inadequate production of thyroid hormones can have serious health-related implications.
Hyperthyroidism is a set of disorders which results from the excessive production of thyroid hormones by thyroid gland.
What are the causes of Hyperthyroidism?
Hyperthyroidism can result from a number of conditions listed below.
- Grave’s disease
Everything in our body is adequately controlled. This stands true for the synthesis of thyroid hormones as well. Normally thyroid hormone synthesis occur only in response to another hormone called Thyroid stimulating hormone (TSH) that is secreted in a controlled manner.
Grave’s disease is characterized by the production of antibodies. These antibodies mimic Thyroid stimulating hormone. They keep stimulating thyroid gland all the time, thus causing hyperthyroidism.
Grave’s disease is the most common cause of hyperthyroidism. It accounts for about 76% of the cases of hyperthyroidism.
- The other causes of hyperthyroidism include;
- Multi-nodular Goiter
- Thyroid adenoma
- Drugs: Amiodarone
What are the symptoms of Hyperthyroidism?
Hyperthyroidism commonly presents with the following symptoms
- Weight loss although they eat more than usual (appetite is increased)
- Increase sweating
- Heat Intolerance
- Protuberant eyes
How to diagnose Hyperthyroidism?
It can be diagnosed by using the following tests
1. Thyroid function tests
- Thyroid stimulating Hormone (TSH) level is low.
TSH is a hormone that regulates the synthesis of thyroid hormones. The secretion of TSH occurs in response to changes in the levels of thyroid hormones. If the thyroid hormone levels get low, TSH is released to raise the levels of thyroid hormones back to normal. Similarly if thyroid hormone level is high TSH synthesis is decreased to avoid any further production of thyroid hormones. Thus, in case of hyperthyroidism it is decreased to almost undetectable levels.
- T3 and T4( thyroid hormones) are elevated
1. Autoantibody detection
We said grave’s disease was caused by antibodies produced by our own body. This is why we can use different tests to detect these antibodies.
2. Thyroid Radioactive iodine Uptake
Thyroid gland takes up iodine in our body and utilizes it to produce thyroid hormones. The more the iodine uptake by thyroid gland the more active it is. We cannot measure the natural iodine that is taken up by the thyroid gland but we can measure the radioactive iodine. We provide the patient with radioactive iodine and measure how much of it is taken up by the thyroid gland. This gives us an idea whether the thyroid gland is hyperactive or not.
How Hyperthyroidism is treated?
There are following three methods available for the treatment of hyperthyroidism
1. Antithydoid drugs
They include drugs such as Carbimazole and Propylthiouracil. These medications work by decreasing the synthesis of thyroid hormones. They can treat hyperthyroidism but the problem with these drugs is that they cannot be used for a longer period of time. This is because they have the potential to decrease the white blood cells, making us prone to many infections.
Most of the clinical manifestations of the hyperthyroidism such as palpitations, anxiety and tremors are mediated by sympathetic nervous system. This drug helps us get rid of these symptoms by taking control of sympathetic system.
We can surgically remove the hyperactive thyroid gland. There will be no production of thyroid hormone. However the patient do need optimum amount of thyroid hormone for normal functioning .This is why to fulfill the normal requirements of thyroid hormone we provide him with exogenous thyroxine.
c) Radioactive Iodine Uptake.
This is a modern method of treating hyperthyroidism. We said Iodine is being utilized by the thyroid gland to produce thyroid hormone. We utilize the same principal here but we use radioactive iodine. Radiations are not good; they are toxic resulting in the destruction of cells of thyroid gland, resulting in a decrease in the levels of thyroid hormone.
Hypothyroidism is a set of disorders resulting from deficiency of thyroid hormone.
What are the causes of Hypothyroidism?
Hypothyroidism can result from a number of important conditions listed below..
- Iodine deficiency:
Iodine is required for the synthesis of thyroid hormones so any deficiency in iodine can cause hypothyroidism. This is an important cause of hypothyroidism in the developing countries. However in the developed countries such as United States of America iodine deficiency is not a problem anymore. This is addressed by the supplementation of Table salt with iodine.
- Hashimotos Disease
This is an autoimmune disease and it is the most common cause of hypothyroidism in United States and other developing countries. It is characterized by the production of antibodies directed against Thyroid gland. These antibodies cause destruction of the thyroid gland and thus a deficiency of thyroid hormones. It occurs more commonly in females.
- Some of the other causes of hypothyroidism are listed below;
- Drugs; Lithium, Amiodorone
- Foods such as turnips
- Genetic problems of Thyroid hormone synthesis
What are the symptoms of Hypothyroidism?
Hypothyroidism affects almost every system of the body in a certain way. Some of the common symptoms of hypothyroidism are listed below.
- Weight gain
- Cold intolerance
- Hoarseness of Voice
- low pulse rate
- Mood changes and Depression
- Erectile dysfunction
- Dryness of the skin
- Loss of hairs
How Hypothyroidism is diagnosed?
Hypothyroidism can be diagnosed by using the following tests.
1. Thyroid Function Tests
- Thyroid Stimulating Hormone (TSH) level is high.
- Serum T3 and T4 will be low
2. Thyroid Antibodies
The most common cause of hypothyroidism in developing countries is Hashimoto’s disease. This is caused by auto antibodies. Thus, we can measure the levels of these antibodies to know whether the cause of hypothyroidism is Hashimoto’s disease or not.
How to Treat Hypothyroidism?
Hypothyroidism can be effectively treated by providing the patient with exogenous thyroid hormone (Thyroxine).The therapy with this hormone is life long and with use of this hormone a person can live a completely normal life.