Hyperthyroidism or overactive thyroid is a condition in which the thyroid gland is overactive and makes excessive amounts of thyroid hormone. Your thyroid is a small butterfly-shaped gland found at the base of your neck, just below your Adam’s apple. This gland makes thyroid hormone that travels in your blood to all parts of your body. The thyroid hormone controls your body’s metabolism in many ways, including how fast you burn calories and how fast your heart beats.
When the thyroid gland is overactive, the body’s processes speed up. You may experience symptoms such as nervousness, anxiety, rapid heartbeat, excessive sweating and sleep problems, among other symptoms. Anyone can develop the disease but it’s more common in women than in men.
Generally, it progresses slowly. The rate can be different in younger people, though. This age group might see their symptoms develop more quickly. Hyperthyroidism has a number of causes and, fortunately, a number of treatment options. It is important you talk to your doctor if you think you may have symptoms of hyperthyroidism.
What Causes Hyperthyroidism?
Many diseases and conditions can cause an overactive thyroid.
Graves disease the most common cause. With this, your body attacks healthy thyroid tissues, causing overactivity. It may also may be caused by goiter, which are lumps or nodules in the thyroid gland. Goiter causes the thyroid to produce excessive amounts of thyroid hormones.
In addition, inflammation of the thyroid gland—called thyroiditis. It results from a virus or a problem with the immune system and may temporarily cause symptoms of hyperthyroidism. Furthermore, some people who consume too much iodine (either from foods or supplements).
Besides, people who take medications containing iodine may cause the thyroid gland to overproduce thyroid hormones. Finally, some women may develop hyperthyroidism during pregnancy or in the first year after giving birth.
What are the signs and symptoms of hyperthyroidism?
At first, you might not notice any signs or symptoms. Symptoms usually begin slowly. But, over time, a faster metabolism can cause symptoms such as:
- Weight loss, even if you eat the same or more food (most but not all people lose weight)
- Eating more than usual
- Rapid or irregular heartbeat or pounding of your heart
- Feeling nervous or anxious
- Feeling irritable
- Trouble sleeping
- Trembling in your hands and fingers
- Increased sweating
- Feeling hot when other people do not
- Muscle weakness
- Diarrhea or more bowel movements than normal
- Fewer and lighter menstrual periods than normal
- Changes in your eyes that can include bulging of the eyes, redness, or irritation
Hyperthyroidism raises your risk for osteoporosis, a condition that causes weak bones that break easily. It might affect your bones before you have any of the other symptoms of the condition. This is especially true of women who have gone through menopause or who are already at high risk of osteoporosis.
To diagnose hyperthyroidism, your doctor may perform one or more of the following tests and procedures:
Physical Exam. First, your doctor may feel the base of your neck to see if your thyroid gland is swollen or enlarged. They might also check to see if you have tremors, bulging of the eyes, overactive reflexes, and a rapid heart rate.
Ultrasounds. To get an even better view of your thyroid gland.
Blood Tests. Here your doctor will measure blood levels of the thyroid hormone thyroxine (T4). The pituitary gland hormone called the thyroid-stimulating hormone (TSH) will also be measured. With hyperthyroidism, you will likely have high T4 but low TSH levels. Your doctor may also order a blood test to measure another thyroid hormone, triiodothyronine (T3), as well as thyroid antibodies that makes the body when the immune system mistakenly attacks the thyroid.
How is hyperthyroidism treated?
Your doctor’s choice of treatment will depend on your symptoms and cause. Treatments include:
- Anti-thyroid medicines block your thyroid from making new thyroid hormone. These drugs do not cause lasting damage to the thyroid.
- Beta-blockers block the effects of thyroid hormone on your body. These medicines can be helpful in slowing your heart rate and treating other symptoms until one of the other forms of treatment can take effect. Beta-blockers do not reduce the amount of thyroid hormones that are made.
- Radio-iodine. This treatment kills the thyroid cells that make thyroid hormones. Often, this causes permanent hypothyroidism.
- Surgery. Thyroid surgery removes most or all of the thyroid. This may cause permanent hypothyroidism.
Each of these treatments has benefits and drawbacks. You’ll normally see a specialist in hormone conditions to discuss which is best for you.