When the Thyroid gland produces too much hormone and is overactive, the body uses energy faster than it should. This condition is called Hyperthyroidism.
Hypothyroidism (low Thyroid function) occurs when the Thyroid gland does not produce sufficient Thyroid hormone to maintain normal body functions.
Causes
Causes of Hyperthyroidism
1. With Graves’ disease, the entire Thyroid gland might be overactive and produce too much hormone.
This is the most common cause (in more than 70% of people)1 of Hyperthyroidism. A person suffers from this condition when antibodies in the blood stimulate the Thyroid gland to grow and secrete excessive Thyroid hormones. This kind of a disorder is usually hereditary and surprisingly, more often than not, young women tend to be its victims.
2. Nodules might be overactive within the Thyroid gland.
Another cause of Hyperthyroidism is also the presence of one or more nodules or lumps in the Thyroid gland that gradually grow and become more active than is usual to release excessive Thyroid hormones into the bloodstream.
3. Thyroiditis (inflammation of the thyroid) can also release hormones that were stored in the Thyroid gland causing Hyperthyroidism for a few weeks or months.
Thyroiditis is usually caused by a problem with the immune system or a viral infection or by the intake of excessive Thyroid hormone in the tablet forms. This disorder can be both painful and painless; the painless variety occurs most frequently in women after childbirth.
4. Presence of excessive Iodine in the body.
A high level of Iodine found in a number of drugs might cause the Thyroid gland to produce excessive hormone in some people.
Causes of Hypothyroidism
1. Autoimmune disease:
Sometimes, the immune system mistakes the Thyroid gland cells and their enzymes as invaders and attacks them. Then, there aren’t enough Thyroid cells and enzymes left to produce Thyroid hormone. This condition is known as Autoimmune Thyroiditis. This incidently, is more common in women than men and may begin suddenly or develop slowly over years.
2. Surgical removal of a part or entire Thyroid gland:
If part or all of your Thyroid gland is removed for a certain reason - Thyroid nodules, Thyroid cancer, or Graves’ disease - chances are that you may begin to suffer from Hypothyroidism due to lack of the Thyroid hormone. In fact, if the whole Thyroid gland is removed, Hypothyroidism is quite a certain result.
If only a part of the gland is removed, Thyroid levels may still remain within normal limits provided the unremoved glands functions optimally.
3. Radiation treatment:
Sometimes, radioactive iodine is used to destroy the Thyroid gland in people who suffer from Graves’ disease, nodular goiter, and Thyroid cancer, Hodgkin’s disease, lymphoma, or cancers of the head or neck. More often than not, all these people lose part or all of their Thyroid function after the treatment.
4. Congenital Hypothyroidism:
Hypothyroidism can also be passed on to an unborn child in the womb. There are babies who are born without the Thyroid gland or with only a partly formed one. A few are even known to have part or all of their Thyroid glands in the wrong place (Ectopic Thyroid). And in some, the Thyroid cells or their enzymes do not function properly.
5. Thyroiditis:
Thyroiditis (an inflammation of the Thyroid gland usually caused by an autoimmune attack or by a viral infection) makes the Thyroid gland release all its stored supply of Thyroid hormone into the blood at one go. This causes a temporary period of Hyperthyroidism and later follows Hypothyroidism. Apart from this, Postpartum Thyroiditis occurs in 5% – 9%
2 percent of women after delivery. However, it is usually a temporary condition.
6. Medicines:
Some drugs can trigger Hypothyroidism and prevent the Thyroid gland from being able to produce the hormones. This is especially true in the case of patients who have a genetic tendency to autoimmune Thyroid disease.
1. Too much or too little iodine
Iodine is very essential for the Thyroid gland to produce the Thyroid hormones. However, keeping the Thyroid hormone production in balance requires the right amount of iodine. Too much of iodine can cause or worsen Hypothyroidism.
2. Damage to the Pituitary gland
If the Pituitary gland (the master endocrine gland that controls the secreation of thyroid hormones) is damaged due to disease or surgery, it may no longer be able to regulate the synthesis and release of thyroid hormones. This may result in decreased levels of Thyroid hormones in the body.
3. Rare disorders that infiltrate the Thyroid gland
Sometimes, in a few people, diseases may deposit abnormal substances in the Thyroid gland and impair its functional ability. For example, Sarcoidosis may deposit granulomas, and Hemochromatosis can cause iron deposition. Hashimoto’s Thyroiditis, a painless disease of the immune system, is hereditary though.
Symptoms of Hyperthyroidism
Since the Thyroid gland controls the body ’s metabolism, it is easy to understand why Hyperthyroidism will show all the results of over-activity and excitement. You will easily be able to recognize Hyperthyroidism from the following symptoms.
Irritability/nervousness
Increased perspiration
Increased heart rate
Muscle weakness/tremors especially in the upper arms and thighs.
Anxiety
Infrequent, scanty menstrual periods
Weight loss
Sleep disturbances
Fine, brittle hair
Skin problems
More frequent bowel movements, but diarrhea is uncommon.
Enlarged Thyroid gland
Vision problems or eye irritation
Heat sensitivity
Hyperthyroidism usually begins slowly. At first, you could even mistake the symptoms for simple nervousness due to stress. In the case of Graves’ disease, the eyes may look enlarged because the upper lids are elevated. Sometimes, the eyes may even bulge. Some people suffering from Hyperthyroidism have a swelling in front of the neck due to a goiter.
Symptoms for Hypothyroidism
The symptoms of Hypothyroidism are so variable and it's diagnosis may be confirmed by performing blood tests.
Diagnosis and Detection of Hyperthyroidism
If your doctor suspects that you are suffering from Hyperthyroidism, he will follow a simple, routine process for the diagnosis. He will ask for a physical examination that may detect an enlarged Thyroid gland and a rapid pulse.
The doctor shall also look for moist, smooth skin and a tremor of fingertips. Your reflexes are likely to be fast, and eyes may bulge in case of Graves’ disease.
These are just the preliminary tests; the diagnosis of Hyperthyroidism is confirmed by laboratory tests that measure the amount of Thyroid hormones— thyroxine (T4) and triiodothyronine (T3)—and Thyroid-stimulating hormone (TSH) in your blood. If your Thyroid gland is overactive, the tests will show a high level of Thyroid hormone in the blood plus a low level of TSH.
In the case of Hyperthyroidism, it is also a routine step for the doctor to ask for a Thyroid scan to find out whether you have a toxic nodular goiter or thyroiditis (thyroid inflammation). At the same time, you may also be advised to test and measure the ability of the gland to collect iodine. Post all this, an endocrinologist (a doctor who specializes in glands and hormones) may be recommended to help you evaluate and determine treatment options.
Detected early, a Thyroid disorder can be brought within control easily, even before the onset of symptoms. And though Thyroid diseases are life-long conditions, with careful management, you can lead a healthy and a normal life.
Diagnosis and Detection of Hypothyroidism
1. Medical and family history
While diagnosing Hypothyroidism, a doctor will always ask about changes in health that suggest that the body is slowing down. He will want to know of any previous record of Thyroid surgery, radiation to the neck to treat cancer and of any medication course that can cause Hypothyroidism. He will also be interested to note any family history of Thyroid disorders.
2. Physical examination
The doctor will check the Thyroid gland and look for changes such as dry skin, swelling, slower reflexes, and a slower heart rate.
3. Blood tests.
The TSH (thyroid-stimulating hormone) test is the most important and sensitive test for Hypothyroidism. TSH is responsible for regulation of synthesis and release of Thyroid homones. An abnormally high TSH indicates Hypothyroidism. The next important set of blood tests is Total T4 and Free T4. It measures the extent of unattached T4 in the blood that is available to enter the cells.
Treatments
Treatment of Hyperthyroidism
On the whole, the treatment of Hyperthyroidism depends on the cause and no single treatment is best for all patients with Hyperthyroidism. Depending on your age, physical condition, type and severity of Hyperthyroidism, your doctor will recommend appropriate therapy.
1. Anti-thyroid drugs3
To begin with, a doctor may choose to prescribe antithyroid agents in order to block the Thyroid gland’s ability to synthesize new Thyroid hormones. These drugs are known to act promptly and do not cause permanent damage to the Thyroid gland. In about 20% to 30% of patients with Graves’ disease, treatment with anti-thyroid drugs for about 12 to 18 months normally results in a prolonged remission of the disease. However, in the case of patients with toxic nodular or multi-nodular goiter, the anti-thyroid drugs may make way for either radioiodine treatment or surgery.
2.
Radioactive iodine
Hyperthyroidism can be treated by destroying the cells that synthesize Thyroid hormones. In this method, Radioactive Iodine is administered by mouth (in a capsule form). Once swallowed, the overactive Thyroid cells quickly take up the radioiodine through the blood stream. Over several weeks, maybe months, radioactive iodine damages the cells that have taken it up and as a result the Thyroid nodules shrink and the level of Thyroid hormones in the blood reduces. Radioactive iodine has been a recommended way of treating Hyperthyroidism for over 60 years now. Today, apart from adults, more and more children are also being treated through this tried and tested method.
3. Surgery
Surgical removal of the entireThyroid gland or a part is the permanent cure for Hyperthyroidism. In this instance before the actual surgery takes place, antithyroid drugs are administrered prior to surgery. Then, for some days before surgery, the doctor may also recommend drops of non-radioactive iodine to reduce the blood supply to the Thyroid gland. This makes the surgery easier and safer. The surgery is safe and; major complications may occur in less than 1%
1 of the patients when operated by an experienced surgeon. If at all, these complications can include damage to the parathyroid glands that control the body’s calcium levels and to the nerves that control your vocal cords. After the Thyroid gland is removed, some patients may become Hypothyroid. However, the hormones levels can be restored by a Thyroid hormone supplement.
4. Beta-blockers
Sometimes, doctors inaddition to the above options may also use Beta-adrenergic blocking agents that block the action of Thyroid hormone on your body. Beta-blockers offer symptomatic relief whithin hours. However, the high levels of Thyroid hormones remain unaltered. This is possible because these drugs help to slow down your heart rate and reduce the symptoms of palpitations, tremors, and nervousness until alternative therapy options produce effect.
Treatment of Hypothyroidism
While Hypothyroidism cannot be cured, it can be well controlled. One way of doing this is through the Thyroxine (T4) replacement process. In this treatment, Thyroxine (T4) is administered externally since the Thyroid gland is unable to synthesize the same. As a result, the T4 and TSH levels return to near normal levels and it helps to restore normal function. However, if you take too little of this medication, Hypothyroidism may continue. If you take too much, you may develop Hyperthyroidism.
Doctors recommend a TSH check about every 6 to 10 weeks after a thyroxine dose change. More tests may be required in case of pregnancy or in case of consuming medicines that may interfere with utilization of Thyroxine. Once the dose regulation is finalized TSH tests may be performed on an yearly basis.
Thyroid Self Test
Click here to download a list of questions you need to ask your doctor when you go for a visit.
References:
1. Hyperthyroidism
Available at: http://www.thyroid.org/patients/patient_brochures/hyperthyroidism.html
Accessed on: 20/07/2010
2. Causes of Thyroid Disorders
Available at: http://www.simplyanswer.com/causes-thyroid-disorders.php
Accessed on: 20/07/2010
3. Hyperthyroidism
Available at: http://www.thyroid.org/patients/patient_brochures/hyperthyroidism.html
Accessed on: 20/07/2010
The growth and development of all body tissues are dependent on the Thyroid gland's proper functioning. If the Thyroid gland is either over-active or under-active, it can create health problems, collectively called as Thyroid disorders.