What is Hashimoto’s disease

Hashimoto’s disease is another name for autoimmune thyroiditis, a condition which develops when a person’s immune system attacks their own thyroid gland. It is the most common cause of hypothyroidism, or decreased thyroid gland function. When the thyroid produces fewer hormones than necessary, many bodily organs and tissues may suffer as a result. Typical symptoms include body mass gain, mood swings or depression, and increased fatigue or weakness. If left untreated, Hashimoto’s can result in severe cardiovascular complications or in a life-threatening condition called myxedema. Nevertheless, with timely diagnostics and treatment, including lifestyle modifications, the symptoms can disappear completely. 

Who gets this disease most often?

Epidemiologists are very clear on this: women get Hashimoto’s much more often than men. A systematic review of publications from 1980 to 2008 reports the incidence of autoimmune hypothyroidism in about 350-500 per 100,000 females per year, while for males, the highest estimated incidence is 80 per 100,000 people. The disease most commonly starts in people of reproductive age.

Aside from being female, other risk factors for Hashimoto’s include having other autoimmune diseases (such as rheumatoid arthritis or type I diabetes), family history of thyroid disorders, and a history of excessive exposure to radiation or iodine. Finally, pregnancy can also be a trigger of Hashimoto’s disease.

Hashimoto’s in women: infertility and pregnancy issues

In addition to the complications listed above, autoimmune thyroiditis can have an effect on women’s reproductive functions. For example, the disease might be accompanied by a decreased libido or inability to ovulate; both these factors can result in infertility and affect the patient’s mental health. Thyroid disease is more prevalent in women who fail to become pregnant, either spontaneously or with the help of assisted reproductive technologies, although no clear causal relationship has yet been established. This means that infertility in these patients is not necessarily caused by the thyroid disorder In fact, both conditions might be provoked by an unknown third factor and develop in parallel.

In women with Hashimoto’s disease, menstruation can become extremely painful, irregular, and with excessive bleeding. In fact, it is a gynecologist’s responsibility to refer all patients with abnormal menstrual cycles for a TSH (thyroid stimulating hormone) blood test. In women with endometriosis, a condition in which abnormally located endometrial tissue makes periods a torture, abnormal thyroid function can worsen the condition. Hashimoto’s disease is also more prevalent in women with polycystic ovary syndrome.

During pregnancy, decreased thyroid function increases the risk of early miscarriage. In addition, hypothyroidism, even when compensated (with normal thyroxine blood levels), is associated with some pregnancy complications and risks for baby’s health.

Postpartum thyroiditis (thyroid gland dysfunction in the months after giving birth) is a frequent condition; according to scientific data; it develops in 6% to 8% of women. Currently, it is thought that all women with postpartum depression, excessive anxiety, or fatigue should have a TSH blood test.

Treatment

Hypothyroidism is treated with hormone replacement therapy: the patient receives thyroid gland hormones to normalize their blood levels and hypophyseal function. Nevertheless, there are specific situations when such treatment may not be required, and it is enough to regularly monitor the patient’s condition. For example, recent studies in women with autoimmune thyroiditis and infertility did not demonstrate any benefits of taking thyroid hormones when patients had normal levels at baseline – their ability to become pregnant did not improve. On the other hand, in pregnant women, even compensated hypothyroidism increases the risk and should be treated with thyroxine.

In addition, general lifestyle improvements, such as regular physical activity and a healthy diet can help reduce symptoms and improve wellbeing. A balanced diet with enough protein, fiber, and healthy fats can be helpful. 

When preparing for the use of assisted reproductive technologies (ART), a woman receives ovarian hyperstimulation. This leads to an increase in estrogen levels in the blood, which, in turn, can severely impact the functioning of the thyroid gland. While in generally healthy women, these changes quickly normalize, in people with autoimmune thyroiditis, such ovarian stimulation can lead to abnormal thyroid function during pregnancy (and thus to additional risks). This means that for women with a thyroid disorder, the benefits and risks of ART should be additionally weighed before using the technology.

Usually, the treatment involves taking a levothyroxine pill once a day. The dosage may need to be adjusted from time to time. For this reason, blood tests are required at least once a year (for adults). In girls, including adolescents, blood levels of thyroid hormones can be measured as frequently as every three months. If a pregnant person is being treated with thyroxine, she may also need several blood tests and dose adjustments throughout the pregnancy.

When taking levothyroxine, it is important to separate it from some medication and dietary supplements – for example, proton pump inhibitors or calcium supplements can slow its absorption. Additionally, biotin, which is often administered as a supplement to help strengthen nails and hair, can affect the results of thyroid function blood tests. It is necessary to stop taking biotin at least 2 days before the blood is drawn. The supplement can be restarted as soon as the blood sample is provided.

Key takeaways

Not only is Hashimoto’s disease more prevalent in female patients, but it can also affect them in more ways – from painful and excessive periods, to infertility, to pregnancy complications. It is extremely important to suspect, diagnose, and treat the disease in a timely manner. In most cases, levothyroxine is indicated, and the dose should be carefully adjusted based on lab results.