Hyperthyroidism involves the thyroid gland producing too much of the thyroid hormones. This overproduction can have different effects in females and males.
A female with hyperthyroidism may have symptoms involving menstruation and pregnancy, while males may experience sexual dysfunction, for example. Hyperthyroidism can also cause a wide range of universal symptoms.
In this article, we describe the general and sex-specific symptoms of an overactive thyroid. We also explain how doctors diagnose the issue and what its treatment entails.
Hyperthyroidism is when the thyroid, a butterfly-shaped gland in the neck, produces an excess of hormones called thyroxine (T4) and triiodothyronine (T3).
The high levels of these hormones can have a broad range of effects on the body. A person may, for example,
- shifts in mood
- muscle weakness
- sensitivity to heat
- difficulty sleeping
- hair loss
- nail changes
- shaky hands
- frequent bowel movements or diarrhea
- unintended weight loss
- heartbeat abnormalities
- difficulty breathing and swallowing
When hyperthyroidism results from an underlying autoimmune disorder called Graves’ disease, a person may also experience:
- eye inflammation
- eye bulging
- a skin condition called pretibial myxoedema, which tends to give the lower legs a swollen, lumpy appearance
Thyroid hormones help regulate the menstrual cycle, and an overproduction may cause:
- disruptions, including irregular or lighter periods
- difficulties becoming pregnant
- health problems during pregnancy for both the person and the fetus
Pregnancy raises the level of thyroid hormones in the blood, and having hyperthyroidism during pregnancy can lead to:
- preeclampsia, a potentially serious condition that causes high blood pressure and kidney problems
- thyroid storm, a severe worsening of hyperthyroidism symptoms
- premature birth
- a birth weight below 5 pounds
- problems with the baby’s heart, including a faster heart rate, which can lead to severe complications
- pregnancy loss
In addition, some researchers have found that hyperthyroidism leads to reduced libido in females.
For males, having an overactive thyroid can cause:
- a low sperm count
- erectile dysfunction
- loss of muscle mass
- breast tissue enlargement
A 2019 review found that the symptoms related to sexual dysfunction were present in 48–77% of males with the disease. Though the evidence was mixed, hyperthyroidism may also lead to low libido in males.
If a doctor suspects hyperthyroidism, they will check the person’s medical history and perform an examination to check their neck for signs of an enlarged thyroid.
The symptoms of hyperthyroidism are broad and
Due to this, rather than relying on symptoms alone, doctors typically order a blood test to check thyroid function. The results reveal the level of thyroid hormones in the blood.
In some cases, additional tests are necessary. For example, a doctor might order an iodine uptake test to determine whether Graves’ disease is responsible for a person’s hyperthyroidism.
The aim of treatment is to bring thyroid hormone levels into the normal range and thereby reduce hyperthyroidism symptoms.
The specific approach depends on several factors, including the person’s age, the presence of other health conditions, and the severity of the symptoms.
Antithyroid medications, such as methimazole (Tapazole), lower the production of thyroid hormones. Doctors usually need to adjust the dosage of these medications over time. They will typically perform blood tests every 2–3 months to ensure the correct dosage, reducing the frequency of these tests to every 6–12 months for long-term treatment.
Doctors may prescribe other medications, as well. Beta-blockers, for example, may help treat symptoms such as nervousness and shaky hands.
Antithyroid medications may lead to side effects, including a lower white blood cell count or liver problems.
Another treatment option is radioiodine therapy, which involves taking a capsule or liquid containing radioactive iodine-131. This substance destroys cells of the thyroid gland without affecting other tissues.
In cases where other treatments are not working, a doctor may recommend surgery to remove some or all of the thyroid gland. This procedure is called a thyroidectomy.
Hyperthyroidism can be difficult to detect because its symptoms are so broad and overlap with those of so many other health issues.
Anyone who suspects that they have a thyroid problem should see a doctor right away. Some warning signs include:
- unexpected changes in weight
- changes in appearance, such as thinning hair and skin
- persistent tiredness and mood changes
- constantly feeling too hot or cold
- missing a period without being pregnant
Hyperthyroidism occurs when the thyroid, a gland in the neck, produces too much of the thyroid hormones. It can cause a broad range of symptoms, some of which are sex-specific.
The condition is more common in females than in males and can cause problems with menstruation and pregnancy. In males, the disease can affect sexual functioning and cause breast tissue enlargement.
Doctors use a blood test to diagnose hyperthyroidism. Several medications and therapies are available, which can reduce symptoms and regulate hormone levels.