Hashimoto’s disease

At a glance

  • Hashimoto’s disease is an inflammation of the thyroid gland.
  • It is caused by an abnormal reaction of the immune system.
  • The inflammation often leads to an underactive thyroid over time. Then the thyroid doesn’t produce enough hormones anymore.
  • The typical symptoms are tiredness and changes in your skin.
  • Then hormone replacement tablets need to be taken.


Photo of woman taking medication

The thyroid gland produces , including two types known as T3 and T4. These regulate many of the processes in our bodies. Hashimoto’s disease is a chronic of the thyroid. Over time, this results in the gland not producing enough anymore. This can lead to various symptoms, such as constant tiredness, problems concentrating, hair loss or changes in the person’s skin.

It is not possible to treat the cause of Hashimoto’s disease. But the symptoms usually go away if you can regulate the hormone levels by taking tablets.


If the thyroid doesn’t make enough hormones, it has a negative effect on a number of body functions. This is reflected in the wide range of symptoms.

Many people feel generally weak, and often tired and cold too. There can be visible changes in the body. For example, the person’s neck can swell because the sometimes results in an enlarged thyroid (known as a “goiter”). Later, the thyroid can also shrink a lot. Their skin may become dry or swollen too, making their face look somewhat puffy. Some people put on weight.

Hoarseness, constipation, a slow heart rate, menstrual (period) problems and erection problems can also occur. Other possible symptoms of an underactive thyroid include mental health problems such as a low mood or lethargy.

Illustration: Possible symptoms of Hashimoto’s disease


The thyroid that occurs in Hashimoto’s disease is caused by an autoimmune reaction: The person's attacks their own thyroid tissue, resulting in chronic . In some cases, this leads to more and more thyroid tissue being lost and replaced by connective tissue.

It is not clear why the makes this mistake. Genetic factors probably play a role: Experts assume that people with certain genes can develop these problems if too much iodine gets into their body. This might happen if they have to be injected with an iodine-containing contrast medium for a CT scan, for example. In day-to-day life, the iodine concentrations in our diets aren't high enough to cause these problems.


Hashimoto's disease affects an estimated 4 out of 1,000 women and 1 out of 1,000 men. It is the most common cause of an underactive thyroid in Germany and other countries. Most of those affected get it between the ages of 30 and 50. But it can occur in children and older people too.


People with Hashimoto’s disease often still have normal levels of thyroid in their blood to start with, even though cells in the thyroid gland are dying. This is because the rest of the thyroid tissue can produce more . But the tissue that’s still working properly needs to grow in order to keep the hormone levels normal. As a result, the thyroid is often bigger than normal at the beginning of the disease (this swelling is called a “goiter”).

At some point, only very little of the thyroid tissue remains and the body can't keep up. and the body can’t produce enough thyroid any more. Then not enough thyroid are produced. This leads to symptoms that are typical of an underactive thyroid.

In rare cases, people with Hashimoto’s disease have an overactive thyroid for a short time at the beginning of the illness. The symptoms include a rapid heartbeat, agitation and increased sweating. This is because stored in the thyroid tissue are suddenly released into the body when the tissue dies.


If your doctor thinks you might have a thyroid problem like Hashimoto's disease, they will ask about your symptoms and examine the thyroid by feeling your neck. And they will often do an ultrasound scan of your thyroid.

The only way to know for sure whether you have a hormone disorder is by doing blood tests. The tests measure the levels of various thyroid in your blood. These include the thyroid themselves and the thyroid-stimulating hormone (TSH). TSH is produced in the pituitary gland in the brain. It controls the function of the thyroid gland.

Good to know:

Hashimoto's disease and other thyroid conditions can be diagnosed using various tests. They are all explained briefly in the "Understanding thyroid tests" information.

These blood tests alone are not enough to detect hypothyroidism. Another test can help to find out whether the cause is Hashimoto's disease. It can detect certain antibodies to the thyroid tissue. Your body makes these antibodies due to an abnormal reaction of the and they can be detected in the blood of most people who have Hashimoto's disease.

Because Hashimoto’s disease can occur in combination with other autoimmune diseases, further examinations are sometimes needed – for instance, to test for gluten intolerance (celiac disease) or diabetes.


When Hashimoto’s disease leads to an underactive thyroid, it’s important to get treatment. If it’s left untreated, complications such as cardiovascular (heart and blood vessel) disease can arise over the long term. Seizures, difficulty concentrating, memory problems, confusion and even comas are also possible but extremely rare.


It is not possible to treat the factors that caused the Hashimoto’s disease to develop. But if the results in an underactive thyroid, you can make up for the lack of T4 thyroid hormone (also known as “thyroxine”) by taking medication called levothyroxine or L-thyroxine. This medication is transformed into a thyroid hormone inside the body to keep the hormone levels within the normal range. The symptoms then usually go away completely. But it takes about two to three months for the hormone levels to return to normal.


L-thyroxine is taken once a day – usually as life-long therapy. Doctors recommend taking the tablet with a glass of water half an hour before breakfast.

Taken at the right dose, side effects are very rare. The dose is determined based on the person’s exact hormone levels, their body weight and other factors. If the dose is too high, it can cause agitation. So the hormone levels are checked regularly during the first few weeks of treatment. If necessary, the dose is changed. After that, the hormone levels usually only have to be checked once a year.

Sometimes treatment is also recommended for Hashimoto’s disease if antibodies are detected in the blood. This is known as “subclinical hypothyroidism.” In these cases, the thyroid gland still manages to make enough , but only because the pituitary gland stimulates it to make more. The treatment is offered in order to prevent symptoms developing.

Further information

When people are ill or need medical advice, they usually go to see their family doctor first. Information about health care in Germany can help you to navigate the German health care system and find a suitable doctor. You can use this list of questions to prepare for your appointment.

Akamizu T, Amino N. Hashimoto's Thyroiditis. Endotext 2017.

Chaker L, Bianco AC, Jonklaas J et al. Hypothyroidism. Lancet 2017; 390(10101): 1550-1562.

Deutsche Gesellschaft für Allgemeinmedizin und Familienmedizin (DEGAM). Erhöhter TSH-Wert in der Hausarztpraxis (S2k-Leitlinie). AWMF-Registernr.: 053-046. 2023.

Jameson JL, Mandel SJ, Weetman AP. Disorders of the Thyreoid Gland. In: D. L. Kaspers, S. L. Hauser, J. L. Jameson et al. (Ed). Harrison's Principles of Internal Medicine. McGraw-Hill Education; 2015.

Jonklaas J, Bianco AC, Bauer AJ et al. Guidelines for the treatment of hypothyroidism: prepared by the american thyroid association task force on thyroid hormone replacement. Thyroid 2014; 24(12): 1670-1751.

Katagiri R, Yuan X, Kobayashi S et al. Effect of excess iodine intake on thyroid diseases in different populations: A systematic review and meta-analyses including observational studies. PLoS One 2017; 12(3): e0173722.

National Institute for Health and Care Excellence (NICE). Thyroid disease: assessment and management. 2019.

Pearce SH, Brabant G, Duntas LH et al. ETA Guideline: Management of Subclinical Hypothyroidism. Eur Thyroid J 2013; 2(4): 215-228.

Schübel J, Feldkamp J, Bergmann A et al. Latente Hypothyreose des Erwachsenen. Dtsch Arztebl Int 2017; 114(25): 430-438.

IQWiG health information is written with the aim of helping people understand the advantages and disadvantages of the main treatment options and health care services.

Because IQWiG is a German institute, some of the information provided here is specific to the German health care system. The suitability of any of the described options in an individual case can be determined by talking to a doctor. informedhealth.org can provide support for talks with doctors and other medical professionals, but cannot replace them. We do not offer individual consultations.

Our information is based on the results of good-quality studies. It is written by a team of health care professionals, scientists and editors, and reviewed by external experts. You can find a detailed description of how our health information is produced and updated in our methods.

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Updated on May 28, 2024

Next planned update: 2027


Institute for Quality and Efficiency in Health Care (IQWiG, Germany)

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