If you have an overactive thyroid (hyperthyroidism), the thyroid produces too many thyroid hormones, so your metabolism is overactive. What are the causes and what symptoms indicate hyperthyroidism?
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Quick overview: Hyperthyroidism
Definition: If you have an overactive thyroid, the thyroid produces more thyroid hormones and releases them into the blood.
Symptoms: Signs include increased sweating, weight loss, nervousness, sleep disorders, high blood pressure, high pulse, cardiac arrhythmias and, in women, changes and disruptions to the menstrual cycle.
Causes: The main causes of hyperthyroidism are the autoimmune disease Graves’ disease and thyroid autonomy (autonomic adenoma).
Diagnosis: To diagnose hyperthyroidism, the blood is tested for the amount of thyroid hormones. An ultrasound of the organ is also carried out.
Treatment: Possible treatment methods include the administration of antithyroid drugs (thyroid blockers), radioiodine therapy and surgical removal of the thyroid.
At a glance:
Hyperthyroidism: These 11 symptoms can occur
What is hyperthyroidism?
If you have an overactive thyroid (hyperthyroidism), the thyroid produces excessive amounts of thyroid hormones and releases them into the blood. As a result, a variety of complaints and metabolic problems arise.
The thyroid gland is located in the lower part of the neck, just below the larynx. It produces various hormones like
- Tetraiodothyronine (T4 or thyroxine) and
- Triiodothyronine (T3).
The organ is involved in many vital metabolic processes and cell growth.
Women are more likely to suffer from hyperthyroidism
Hyperthyroidism is one of the most common thyroid diseases – after goiter (goiter), in which the butterfly-shaped organ is pathologically enlarged. Hyperthyroidism affects ten times more women than men. Overall, the disease occurs in around one percent of all people. Hyperthyroidism usually develops in middle adulthood.
Hyperthyroidism: symptoms of hyperthyroidism
An overactive thyroid is accompanied by a variety of symptoms, although not all symptoms necessarily have to occur. In many of those affected, the thyroid gland is visibly swollen (goiter, goiter), but this does not necessarily have to be the case. In Graves’ disease, the cause of hyperfunction is the bulging eyeballs (exophthalmos).
The most important symptoms, which can usually be traced back to increased metabolic activity, are:
- Nervousness, inner restlessness, aggressiveness, mood swings
- sleep disorders
- accelerated pulse
- Cardiac arrhythmias such as palpitations, rapid heartbeat or atrial fibrillation
- increased blood pressure
- increased sweating, increased body temperature, sensitivity to heat
The following symptoms of hyperthyroidism can also occur:
- Weight loss despite increased appetite
- Loss of performance with weakness and fatigue
- Muscle cramps, muscle weakness, muscle tremors (tremors)
- Diarrhea, sometimes vomiting
- moist, warm, velvety skin
- brittle fingernails and hair
- Hair loss
In women, hyperthyroidism can also lead to disruptions in the menstrual cycle.
Danger to life due to a thyrotoxic crisis
An undetected, insufficiently treated hyperthyroidism, discontinuation of thyroid medication or excessive iodine intake (medications containing iodine) can have serious consequences: a thyrotoxic crisis. Within a short period of time, the metabolism becomes life-threatening. The symptoms of hyperthyroidism are extremely pronounced. Heart palpitations, impaired consciousness, high fever and tremors occur. Thyrotoxic crisis is a medical emergency that requires immediate treatment.
Causes: Common triggers of hyperthyroidism
Hyperthyroidism is not an independent disease, but a symptom caused by another underlying disease. Graves’ disease or thyroid autonomy (“hot nodule”) are almost always responsible.
Graves’ disease: Graves’ disease is an autoimmune disease in which the body’s own immune cells attack the thyroid. The result is chronic inflammation, which stimulates hormone production.
Thyroid autonomy: How much hormone the thyroid should produce is determined by the pituitary gland. If many cells in the thyroid no longer respond to the control instructions of the pituitary gland, hormone production gets out of control. Experts then speak of thyroid autonomy, functional autonomy of the thyroid or an autonomous adenoma. The autonomous cells often form one or more overactive nodes. In other cases, the entire thyroid is affected.
Hyperthyroidism can also be triggered by drug treatment of an underactive thyroid. Other, rarer causes can be:
Hyperthyroidism: How is it diagnosed?
If hyperthyroidism is suspected, the exact symptoms and history of the disease will be asked in a detailed anamnesis. This is followed by a palpation examination of the thyroid gland. In this way, any enlargement or any lumps that may be present can be identified. If the thyroid gland can be felt, this indicates a goiter, which is a common sign of hyperthyroidism.
Determination of thyroid hormones in the blood
It is important to determine the concentration of thyroid hormones in the blood (blood test). The amounts of free thyroxine and triiodothyronine (fT4 and fT3) are measured. The laboratory also determines the concentration of the thyroid-stimulating hormone TSH (thyrotropin, thyrotropic hormone). TSH is produced by the pituitary gland. If the levels are low, the thyroid produces an excess of thyroid hormones.
If the TSH value is low and T3 and T4 are elevated at the same time, the diagnosis of hyperthyroidism is almost certain. If antibodies against the thyroid tissue (TSH receptor autoantibodies, TRAK) can be detected, Graves’ disease is the cause of the hyperthyroidism.
Imaging procedures
The tissue of the thyroid gland can be easily examined for changes using ultrasound. Nodes also become visible. Scintigraphy is a nuclear medicine examination method. They can be used to check thyroid function. It shows, for example, whether a node produces increased hormones, i.e. whether it is a “hot node”.
Therapy: How is hyperthyroidism treated?
Whether treatment is necessary depends on the severity of the hyperfunction. If therapy is necessary, there are three different ways to treat hyperthyroidism.
Medication: So-called antithyroid drugs reduce the production of thyroid hormones or their release into the blood.
Radioiodine therapy: During radioiodine therapy, radioactive iodine is taken, which is stored in the thyroid gland and switches off hyperactive cells there. This therapy is particularly useful in cases of thyroid autonomy as the cause of the hyperfunction. Radioiodine therapy is unsuitable for children and pregnant women. A side effect of radioiodine therapy can be hypothyroidism. Since patients are radioactive for a short time after treatment, they are isolated in specialized radiation protection rooms after taking the iodine.
Surgery: Thyroid surgery is advisable if the hyperthyroidism is severe and medication and radioiodine therapy have not brought sufficient success.
The treating doctors decide which treatment is suitable. Various factors play a role in this decision, such as the causes as well as the age and health status of the patient.
Course and chances of recovery for hyperthyroidism
It is important to recognize and treat hyperthyroidism in a timely manner. Therefore, you should always seek medical help if you have any symptoms.
If Graves’ disease is the cause, the hyperthyroidism often regresses when taking antithyroid drugs. However, despite therapy, a relapse can occur years later. Regular thyroid checks and thyroid levels are therefore important.
After radioiodine therapy and surgery, an underactive thyroid often develops. Those affected must take medication to combat the resulting hypothyroidism because the body does not produce sufficient amounts of thyroid hormones. Taking hormones usually does not cause any side effects.
Can hyperthyroidism be prevented?
Hyperthyroidism cannot be specifically prevented. However, sufficient iodine supply prevents thyroid enlargement. Because a dietary iodine deficiency causes goiter – the thyroid gland grows to compensate for this deficiency.
Foods containing iodine: The best sources of iodine
