Thyrotoxic Crisis

By | June 10, 2022

The term thyrotoxic crisis describes a sudden and life-threatening metabolic imbalance. It usually develops on the basis of an existing hyperthyroidism.

What is Thyrotoxic Crisis?

The thyrotoxic crisis is a life-threatening derailment of an overactive thyroid gland ( hyperthyroidism ). The clinical picture develops within a few hours or days. In the thyrotoxic crisis, all the symptoms of hyperthyroidism are very severe. For hysteria dictionary definitions, please visit

The crisis is often triggered by increased iodine intake or by X-ray contrast media containing iodine. The thyrotoxic crisis occurs approximately one to four weeks after admission. Discontinuation of antithyroid drugs can also cause a thyrotoxic crisis. The crisis requires immediate intensive care. If left untreated, it can lead to death.


A thyrotoxic crisis can only develop from an overactive thyroid. With an overactive thyroid, the thyroid produces too much thyroid hormone. The two most important thyroid hormones are triiodothyronine (T3) and thyroxine (T4). The basic component of the thyroid hormones is the trace element iodine. The main cause of hyperthyroidism is Graves’ disease, an autoimmune disease.

The body’s own antibodies bind to the TSH receptors in the thyroid gland and thus mimic the effect of the thyroid-stimulating hormone (TSH) from the pituitary gland. This leads to a constant production of T3 and T4 and thus to an overactive thyroid gland. Hyperthyroidism can also develop as a result of thyroid autonomy. With thyroid autonomy, individual areas of the thyroid work independently of the hormonal regulatory mechanisms.

Hyperthyroidism can also be caused by hormone-producing thyroid tumors and thyroid inflammation. Thyrotoxic crisis usually develops after high iodine intake. As a result, the body has more iodine available for the production of thyroid hormones. Since the body’s own hormonal regulation mechanisms are disturbed in the case of hyperthyroidism, production is not curbed.

The thyrotoxic crisis is often iatrogenic, i.e. induced by the doctor through the administration of iodine-containing drugs. X-ray contrast media are also common triggers. It also becomes dangerous when patients with an overactive thyroid stop taking their medication on their own. Antithyroid drugs stop the thyroid from producing too many hormones.

Suddenly stopping the medication can result in a thyrotoxic crisis. Operations can also cause a thyrotoxic crisis. Especially after the removal of thyroid tissue, the hormone production of the thyroid gland can increase reactively.

Symptoms, Ailments & Signs

Typical symptoms of an overactive thyroid include insomnia, irritability and nervousness. A fine tremor, a slight tremor, can be observed in many patients as a sign of restlessness. The entire metabolism is stimulated by the thyroid hormones. Blood pressure is high.

The difference between the systolic and diastolic blood pressure values ​​(blood pressure amplitude) is increased. The heart activity is changed. The heart beats faster, some of those affected suffer from cardiac stumbling (extrasystoles). Atrial fibrillation can also be the result of hyperthyroidism. The patients are hungry due to the increased energy consumption, but still lose weight.

Due to the mobilization of glycogen reserves and fat reserves, excess blood sugar ( hyperglycaemia ) can occur. Patients sweat profusely, are heat intolerant, and have clammy, warm skin. You need to go to the toilet more often and have loose stools. The muscles are weak. In the thyrotoxic crisis, all of these symptoms intensify massively and within a very short time.

In stage I thyrotoxic crisis, the heart rate is increased to more than 150 beats per minute. Patients vomit and have a high fever. Exsiccosis can develop as a result of the increased fluid excretion. In stage II of the crisis, patients are increasingly disoriented and clouded in consciousness. You are dizzy or sleepy. In stage III, the patients fall into a coma.

The increased heart rate, cardiac arrhythmias and dehydration are particularly threatening. If left untreated, the coma threatens with irreversible long-term effects. Overall, the prognosis of thyrotoxic crisis is rather poor. It often ends fatally.

Diagnosis & course of disease

A suspected diagnosis can be made quite quickly based on the characteristic symptoms. An already known hyperthyroidism provides the decisive clue. The elevated thyroid values ​​can be detected in the blood during a thyrotoxic crisis. The TSH value is greatly reduced.

TSH stimulates the thyroid gland to produce thyroid hormones. However, since there are far too many thyroid hormones in the blood due to the thyrotoxic crisis, the pituitary gland produces less TSH. The levels of the thyroid hormones T3 and T4 are still elevated.


If a thyrotoxic crisis sets in, this affects the entire metabolism. Blood pressure is elevated, nervousness, irritability, and sleep disturbances occur, and tremors set in. In addition, heart activity is altered and those affected suffer from heart palpitations and atrial fibrillation – both of which can lead to serious complications including heart failure.

The general symptoms are accompanied by weight loss, which is usually associated with dehydration and deficiency symptoms. The mobilization of glycogen and fat reserves can lead to hyperglycemia. In addition, the patients are physically ailing and suffer from muscle weakness. In the thyrotoxic crisis, all these symptoms increase within a very short time. High fever, dehydration and disturbances of consciousness occur relatively quickly.

The patient then falls into a coma. Loss of consciousness usually has irreversible long-term consequences or even death if treatment is not given or is treated too late. The treatment of a thyrotoxic crisis can be affected by the typical side effects and interactions of prescribed drugs. A surgical procedure is always risky, since the patient is usually already considerably weakened.

When should you go to the doctor?

High blood pressure, inner restlessness, nervousness and irritability are complaints that should always be clarified by a doctor. If they persist for several weeks or months, they need to be examined. If the irregularities increase, a doctor’s visit is necessary immediately. If there are cardiac arrhythmias, a decrease in muscle strength or a loss of general resilience, we recommend consulting a doctor. Fever, vomiting, malaise, and feeling sick should be presented to a doctor. Since the thyrotoxic crisis is a health emergency, acute changes in well-being often occur within a short period of time.

In the event of sudden discrepancies, an emergency service should be alerted. It is characteristic of the disorder that those affected lose weight beforehand, even though they take in an unusually large number of calories every day. Unwanted weight loss is a warning signal from the body. An ambulance must be called in the event of disturbances in consciousness, disorientation and disturbances in memory. Persons present are obliged to apply first aid measures. Without timely and professional medical care, the affected person is at risk of a comatose state and irreparable damage to organs. There is therefore an acute need for action if there is a significant deterioration in health.

Treatment & Therapy

Thyrotoxic crisis is always treated in the intensive care unit. The functions of the cardiovascular system are closely monitored. In addition, fluid intake and fluid excretion are monitored. In this way, a fluid balance can be carried out and dehydration can be counteracted. Those affected receive three to four liters of fluid per day. Drugs are also used that limit the production and release of thyroid hormones.

These include antithyroid drugs such as thiamazole and glucocorticoids such as prednisolone. The increased heart rate is regulated with beta-blockers. If you have a high fever, you can use ice packs to cool down. Paracetamol or ibuprofen can also reduce the fever. If patients are very restless, sedation can be used.

If the thyrotoxic crisis was triggered by iodine contamination and none of the measures described help, the thyroid gland is almost completely removed in a surgical procedure. Plasmapheresis can also be used to remove iodine from the blood.


Consistent treatment of hyperthyroidism can usually prevent a thyrotoxic crisis. Patients with known hyperthyroidism should not take medications high in iodine. The thyroid function should also be checked in special situations, such as infections or operations.


Unlike an overactive thyroid, the thyrotoxic crisis is life-threatening. It does not develop chronically, but takes on a fulminant course. However, the crisis is usually preceded by an overactive thyroid gland. Timely medical intervention is necessary to prevent a life-threatening outcome of the disease.

In such cases, treatment and aftercare run in parallel. The aim of the therapy is to normalize the thyroid values ​​and to avert the life-threatening condition. The danger to life is not the same in every thyrotoxic crisis. In the early stages, a lethal outcome is about 10 percent likely, in the advanced course the probability is already 30 percent.

The last option in severe cases is surgical reduction of the thyroid gland. However, immediate treatment is always necessary. The patient is hospitalized for this purpose. When the appropriate medicine is given, the responsible internist checks the healing. In addition, the person concerned receives medication for other symptoms such as nausea or dizziness.

If the crisis has been successfully contained, the aftercare is gradually discontinued and ends with the discharge. In the case of a thyroid operation, the usual follow-up methods are scheduled. The family doctor carries out occasional follow-up checks. The patient must keep the appointments so that possible new changes in the thyroid gland can be recognized early.

You can do that yourself

Thyrotoxic crisis is a medical emergency because the patient’s condition can deteriorate rapidly and can lead to death. It is therefore of the utmost importance that patients do not try to alleviate their condition through self-help measures. This is not possible and increases the risk of dying as a result of the thyrotoxic crisis.

If people notice symptoms of a thyrotoxic crisis in themselves or experience any other severe discomfort, contact an emergency doctor immediately. Once under medical treatment, patients with thyrotoxic crisis follow all instructions from staff, whether they are doctors or nurses.

People with a thyrotoxic crisis usually first come to a clinic and are treated as inpatients until their health has improved. For this purpose, the patients receive appropriate medication in the prescribed dose. Taking these medicines regularly and properly is essential, otherwise the symptoms may come back. Digestive problems are also treated with medication, and the patients receive adequate meals in the hospital. Since many of those affected suffer from nervousness, sedatives are sometimes used.

Thyrotoxic Crisis