The thyroid is a small gland that is located at the front of our neck. It produces tetraiodothyronine (T4) and triiodothyronine (T3), the two primary hormones that control our cells to use energy. It is in the shape of a butterfly. Hyperthyroidism is when the thyroid, the butterfly-shaped gland at the bottom of our neck, just above our collarbone, makes too much of a hormone called thyroxine. Our thyroid controls things like how fast our heartbeats and how quickly we burn calories. It releases hormones to control our metabolism. Hyperthyroidism can speed up our metabolism and cause unpleasant symptoms. It occurs when the thyroid makes too much T4, T3, or both.
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Front and back view of the thyroid gland
There are many causes of hyperthyroidism. Mostly the entire gland is overproducing thyroid hormone. Less commonly, a single nodule is responsible for the excess hormone secretion, known as a "hot" nodule.
Graves’ Disease - This immune system disorder is the most common cause of hyperthyroidism and is more likely to affect women under the age of 40.
Thyroid Nodules - These lumps of tissue in our thyroid can become overactive, creating too much thyroid hormone.
Thyroiditis - An infection or an immune system problem can cause our thyroid to swell and leak hormones. This is often followed by hypothyroidism, in which our thyroid doesn’t make enough hormones.
Excess iodine, a key ingredient in T4 and T3
Thyroiditis, the inflammation of the thyroid, causes T4 and T3 to leak out of the gland.
Tumors of the ovaries or testes
Benign tumors of the thyroid or pituitary gland.
High amounts of T4, T3, or both can cause an excessively high metabolic rate. This is called a hypermetabolic state. In this state, we may experience a rapid heart rate, elevated blood pressure, hand tremors, sweat a lot and develop a low tolerance for heat.
Hyperthyroidism causes frequent bowel movements, weight loss, and irregular menstrual cycles in women.
The thyroid gland can swell into a goiter itself that is either symmetrical or one-sided.
Our eyes may also appear quite prominent, which is a sign of exophthalmos, a condition that’s related to Graves’ disease.
increase in appetite
inability to concentrate
difficulty in sleeping
fine and brittle hair
nausea and vomiting
breast development in men
The following are symptoms that require immediate medical attention:
shortness of breath
loss of consciousness
fast, irregular heart rate
Hyperthyroidism can also cause atrial fibrillation, a dangerous arrhythmia that can lead to strokes, as well as congestive heart failure.
Diagnosis of overactive thyroid and treatment of the underlying cause can relieve symptoms and prevent complications. The doctor will ask the patient about his medical history and look for symptoms including a swollen thyroid, a fast pulse, moist skin, and shaking in the patient’s hands or fingers. They’ll give tests that include:
Thyroid Panel - It’s a blood test that measures levels of thyroid hormones and thyroid-stimulating hormone (TSH).
Thyroid Scan - A technician injects a small amount of radioactive iodine into our bloodstream. The thyroid absorbs it and a special camera takes pictures of the gland to look for nodules or other signs of problems.
Ultrasound - A technician runs a device called a transducer over your neck which uses sound waves to create images of our thyroid.
Radioactive Iodine Uptake Test - We swallow a small amount of radioactive iodine. A device called a gamma probe measures how much of the iodine collects in our thyroid. If this uptake is high, the patient has Graves’ disease or thyroid nodules.
T4, Free T4, T3 - These tests measure how much thyroid hormone (T4 and T3) is in our blood.
Triglyceride Test - Low triglycerides can be a sign of an elevated metabolic rate.
More than 27 million American citizens have some type of thyroid disease. About 13 million don’t know that they suffer from a thyroid imbalance.
Women suffer more from thyroid issues than men.
Thyroid disease becomes more common as we age.
Iodine is necessary to form both T3 and T4. Populations around the world with iodine-deficient soil are known to have thyroid issues.
T4 is in the same structure as T3. The only difference is that it has an extra iodine molecule that makes it an inactive form.
The conversion of T4 into T3 occurs not only in the liver but also in cells of the heart, muscles, gut, and nerves. It is important that our liver functions properly for T3 to be produced and become active.
T3 affects the nutrient absorption from carbohydrates and fats, the rate of protein creation and food digestion, muscle building, oxygen utilization in cells, and energy production efficiency in the cells.
1. Why are men less likely to have problems in their thyroid as compared to women?
Hyperthyroidism (overactive thyroid) and hypothyroidism (underactive thyroid) are both typically started by an autoimmune reaction. Graves’ disease commonly causes hyperthyroidism and Hashimoto’s disease commonly causes hypothyroidism. Both diseases are started by the body attacking the thyroid gland. It’s not completely clear about why men have less autoimmune disease than women. Researchers suspect that it has to do with the differences in the immune system. Women have been found to have a more intense immune response to vaccinations, trauma, and infections, compared to men. So, it might be that this highly active immune system puts women at risk for more thyroid disease.
2. How to treat hyperthyroidism?
Medication - Antithyroid medications, like methimazole, stop the thyroid from making hormones.
Radioactive Iodine - Radioactive iodine, given to adults with hyperthyroidism, effectively destroys the cells that produce hormones. Common side effects are dry mouth, dry eyes, sore throat, and changes in taste. Precautions should be taken for a short time after treatment to prevent radiation spread to others.
Surgery - A section or all of the patient's thyroid gland may be surgically removed. The patient will then have to take thyroid hormone supplements to prevent hypothyroidism that occurs when a person has an underactive thyroid.
Beta-Blockers - These medications don’t treat our levels of thyroid hormone but can help with symptoms like anxiety, shaking, or a fast heartbeat.