Hyperthyroidism is when the thyroid gland becomes overactive and produces too much of thyroxine hormone, which results in unintentional weight loss and rapid heartbeat.
The thyroid is a butterfly-shaped gland, which is present in your neck. This gland releases T3 (Triiodothyronine) and T4 (Tetraiodothyronine), which are hormones that regulate the metabolism in the body.
When the thyroid gland secretes too much of T3, T4, or both, it is called hyperthyroidism or overactive thyroid. Overproduction of these hormones affects many functions of the body. This condition can result from various causes and can lead to many symptoms. It affects women more commonly than men and is commonly seen in people who are 60 years or older.
Many factors cause the thyroid gland to become overactive. Some of the common causes are:
Graves’ Disease - It is an autoimmune condition and is responsible for more than 70 % of hyperthyroidism cases. It is genetic and causes the eyes to protrude. Patients usually suffer from discomfort in the eyes and double vision.
Nodular Thyroid Disease - This condition causes noncancerous lumps to develop in the thyroid gland. They make the thyroid gland overactive.
Thyroiditis - Viral infection of the thyroid that results in inflammation is called thyroiditis.
Increased Iodine Intake - The thyroid gland uses the iodine from the blood to produce thyroid hormones. Thus, increased intake of iodine makes the thyroid gland absorb too much iodine, which results in overproduction of thyroid hormones.
Follicular Thyroid Cancer - The cancer cells start producing thyroid hormones in addition to the healthy cells.
Medications - Medicines that contain high amounts of iodine can result in hyperthyroidism. Examples are Amiodarone, Lithium, etc.
Taking Too Much Thyroid Hormone Medicine - If you are under treatment for hypothyroidism, it is crucial to check your hormone levels every year, as taking too much thyroid hormone medicine might result in hyperthyroidism.
Mild hyperthyroidism usually does not cause any symptoms and goes unnoticed. The symptoms seen are different for different people. The most common symptoms include:
The thyroid gland enlarges, which causes swelling in the neck (goiter).
Lack of concentration.
Intolerance to heat.
Frequent bowel movement.
Fine and brittle hair.
Menstrual periods are lighter or absent.
Hair loss occurs in patches (alopecia).
Sudden weight loss.
Tremors in palms and hands.
Nails become loose.
Thinning of the skin.
It also causes increased thirst and tiredness for diabetic patients, and heart failure and arrhythmias in patients with heart problems.
Some of the factors that increase the risk of hyperthyroidism are:
Family history of the disease.
Presence of any chronic illness like diabetes (type 1), vitamin B12 deficiency, and primary adrenal insufficiency.
This condition can result in a lot of complications like:
Graves’ Ophthalmopathy - The eyes of people with hyperthyroidism becomes protruded, swollen, red, sensitive to light, and develop double vision. It can also result in blindness if left untreated.
Osteoporosis - As high levels of thyroid hormones interfere with the absorption of calcium into the bones, it results in weak and brittle bones.
Atrial Fibrillation - Hyperthyroidism can also lead to atrial fibrillation, where the heart beats rapidly, which increases the risk of a stroke and congestive cardiac failure.
Graves’ Dermopathy - The skin becomes red and swollen. It usually affects the skin of the shins and feet.
Thyrotoxicosis Crisis or Thyroid Storm - It is a medical emergency, which causes high fever, rapid heartbeat, jaundice, vomiting, diarrhea, dehydration, and delirium.
Your doctor might suspect hyperthyroidism if you have some of the signs and symptoms as mentioned above. He or she will ask you to swallow and will examine the thyroid gland for any swelling, bumpiness, or tenderness.
To confirm the diagnosis, you have to get the following blood tests done:
T3 and T4 - If your blood reports show high levels of thyroxine (T3 and T4), it indicates hyperthyroidism.
Thyroid-stimulating hormone (TSH) - TSH is the hormone secreted from the pituitary gland, which signals the thyroid gland to release thyroxine. Low or absence of TSH indicates that your thyroid gland is overactive.
Cholesterol and Triglycerides - Low levels of triglycerides and cholesterol indicate an elevated metabolic rate.
If you have hyperthyroidism, your doctor will suggest you take the following tests to know the cause:
Thyroid ultrasound - An ultrasound is done to measure the size of the gland, and to see the presence of any mass or cysts.
Radioiodine uptake test and thyroid scan - Here, the amount of iodine absorbed by the thyroid gland is seen, after administering an oral dose of radioactive iodine. If the gland absorbs too much iodine, it indicates overproduction of thyroxine.
CT or MRI scans - It is used to diagnose a tumor of the pituitary gland, which might also cause this condition.
The following treatment options help manage symptoms and reduce the production of thyroid hormones.
Beta-blockers - They help ease symptoms like tremors, rapid heartbeat, and heart palpitations. It is used until the hormone levels come back to normal.
Antithyroid medicines - Drugs like Methimazole and Propylthiouracil (PTU) stop the thyroid gland from producing too much T3 and T4. It usually takes about a year or more for the hormones to come back to normal.
Radioactive iodine - Radioactive iodine which when taken orally gets absorbed by the gland, which causes the gland to shrink.
Thyroidectomy - Here, the thyroid gland is partially or completely removed. The disadvantage is, you have to take Levothyroxine for the rest of your life to supply sufficient amounts of thyroid hormones to the body.
Take supplements or food rich in vitamin D and calcium, as you are susceptible to develop osteoporosis. Reduce the intake of iodine, as it can worsen your symptoms. Even some multivitamins and cough syrup contain a lot of iodine.
To prevent Graves’ ophthalmopathy and dermopathy, some preventive measures that you can apply are:
Prevent your eyes from drying out by using lubricative gel or drops.
Wear sunglasses when you go out in the sun.
Use pillows to keep your head elevated, as this will reduce swelling and relieve pressure on your eyes.
For redness of the skin, try using creams containing Hydrocortisone.
To know more about the treatment options for hyperthyroidism, consult an experienced and professionally trained endocrinologist online.
Last reviewed at:
24 Jun 2019 - 5 min read
MBBS, MD MEDICINE, FELLOWSHIP IN DIABETES AND ENDOCRINOLOGY, SENIOR RESIDENCY DIABETES AND ENDOCRINOLOGY
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