The thyroid produces hormones that regulate metabolism in the body, among other things. In hyperthyroidism, hormone production is elevated. It provides a high metabolic rate which can cause palpitations, fatigue, fever and weight loss. Treatment consists of medicines that inhibit hormone production but surgery may also be needed.
The thyroid gland is located on the front of the neck, just below the larynx. It belongs to the body’s hormonal system and secretes hormones that control metabolism – how the body’s cells use energy. Hormones affect heart rate, body temperature, muscle strength and many other functions of the body.
Two areas of the brain, the hypothalamus, and the pituitary gland, control the hormone balance in the blood and the number of thyroid hormones to be produced and secreted.
Hyperthyroidism means that you have excess thyroid hormone in your blood. Thyroid disease is more common in women.
There are many different names for hyperthyroidism depending on the cause of the disease – sometimes the same disease can also have several names. The most common cause of hyperthyroidism in young and middle-aged people is Graves’ disease. It is also called Basedow’s disease, diffuse autoimmune hyperthyroidism, toxic diffuse trauma and venom trauma.
Untreated hyperthyroidism can lead to heart failure, heart attack, angina, atrial fibrillation and osteoporosis.
There are several causes of hyperthyroidism. Most commonly, the entire gland is overproducing thyroid hormone. Less commonly, a single nodule is responsible for the excess hormone secretion, called a “hot” nodule. Thyroiditis (inflammation of the thyroid) can also cause hyperthyroidism. Functional thyroid tissue producing an excess of thyroid hormone occurs in a number of clinical conditions.
The major causes in humans are:
- Graves’ disease. An autoimmune disease (usually, the most common cause with 50-80% worldwide. Thought to be due to varying levels of iodine in the diet. It is eight times more common in females than males and often occurs in young females, around 20 – 40 years of age.
- Toxic thyroid adenoma
- Toxic multinodular goiter
High blood levels of thyroid hormones (most accurately termed hyperthyroxinemia) can occur for a number of other reasons:
- Inflammation of the thyroid is called thyroiditis. There are several different kinds of thyroiditis including Hashimoto’s thyroiditis (Hypothyroidism immune-mediated), and subacute thyroiditis (de Quervain’s). These may be initially associated with secretion of excess thyroid hormone but usually progress to gland dysfunction and, thus, to hormone deficiency and hypothyroidism.
- Oral consumption of excess thyroid hormone tablets is possible (surreptitious use of thyroid hormone).
- Amiodarone, an antiarrhythmic drug, is structurally similar to thyroxine and may cause either under- or overactivity of the thyroid.
- Postpartum thyroiditis (PPT) occurs in about 7% of women during the year after they give birth. PPT typically has several phases, the first of which is hyperthyroidism. This form of hyperthyroidism usually corrects itself within weeks or months without the need for treatment.
- A struma ovarii is a rare form of monodermal teratoma that contains mostly thyroid tissue, which leads to hyperthyroidism.
- Excess iodine consumption notably from algae such as kelp.
Thyrotoxicosis can also occur after taking too much thyroid hormone in the form of supplements, such as levothyroxine (a phenomenon known as exogenous thyrotoxicosis, alimentary thyrotoxicosis, or occult factitial thyrotoxicosis).
Hypersecretion of thyroid stimulating hormone (TSH), which in turn is almost always caused by a pituitary adenoma, accounts for much less than 1 percent of hyperthyroidism cases.
Symptoms of hyperthyroidism
The symptoms of hyperthyroidism can be numerous and come on gradually. They include:
- palpitations and increased heart rate
- sweating and heat intolerance
- stress, nervousness and anxiety
- muscle weakness
- frequent bowel movements
- involuntary weight loss
- hair loss
- irregular menstruation in women
- eye symptoms
Normally, the thyroid gland is not visible, but it can grow and become enlarged by the various forms of thyroid disease, which is called a goiter. You may have symptoms of hyperthyroidism with or without goiter.
The symptoms of hyperthyroidism may be similar to other conditions, such as fever, heart failure, high stress, anxiety, alcohol withdrawal and menopausal disorders in women.
Prevention and protection
There is no known way to prevent hyperthyroidism. However, smoking cessation is important in pronounced eye symptoms, such as in Graves’ disease.
If you are treated with medicines, it is important that you follow your prescription correctly.
Blood tests show if you have hyperthyroidism. Free T4 (thyroxine) and T3 (triiodothyronine) and TSH (thyroid-stimulating hormone) are measured. In some cases, thyroid antibodies may also be measured.
In addition to blood tests, a doctor needs to physically examine the thyroid gland to see if there are any lumps, soreness or altered shape. At the same time, you can measure your blood pressure, do an ECG and have your reflexes examined.
If you have heart palpitations, tremors or anxiety, you may be given symptom-relieving medication by prescription.
Other studies, such as ultrasound and biopsy, can supplement the investigation of thyroid disease and its severity.
Hyperthyroidism is treated by a specialist in thyroid disease. The treatment is adapted to the type of hyperthyroidism, your age, whether you are pregnant, breast-feeding or wishing to become pregnant.
In most cases of hyperthyroidism, thyroid medicine is given, a drug that inhibits thyroid hormone production. Some types of hyperthyroidism are treated with radioactive agents, which is a type of local radiation therapy. It is not used if you are or would like to become pregnant, or if you are breast-feeding.
In some cases, surgery may be needed to partially or completely remove the thyroid gland.
It is not uncommon for hyperthyroidism to become hypothyroidism after treatment – in such cases the thyroid hormone is administered in tablet form to balance hormones.
When to consult a doctor
If you have fatigue in combination with heart palpitations, increased heart rate, sweating, anxiety and have lost weight, you should consult a doctor.
If you are treated for hypothyroidism and lose weight quickly, in combination with fatigue, anxiety, and palpitations, you should also contact your doctor.
Seek urgent care in case of soreness or pain in the thyroid gland in combination with a feeling of illness or fever, anxiety, restlessness, palpitations and weight loss.
How Appotek can help
APPOTEK can help with hyperthyroidism.
A nurse or physician will make an individual assessment based on your symptoms, after which you may be prescribed treatment or referred for further examination.
In the case of hyperthyroidism, a physical examination is required.
Bear in mind that if your child has a problem, he or she should see a doctor.
Our psychologists can help with supportive conversations if you have been diagnosed and need someone to talk to.