Hashimoto’s disease is an autoimmune disorder. Hashimoto’s disease damages your thyroid function and can cause hypothyroidism, or underactive thyroid. It’s also called chronic autoimmune lymphocytic thyroiditis. The function of your thyroid is to release hormones into the body. These regulate metabolism, body temperature, muscle strength, and many other functions in the body. With Hashimoto’s disease, your immune system attacks your thyroid. This causes damage to your thyroid which can’t make enough thyroid hormones. The thyroid is a small gland situated at the front of the neck.

It is not clear why the white blood cells and antibodies mistakenly attack the cells of the thyroid, but some believe genetic factors may be involved as Hashimoto’s disease often runs in families. It also affects more women than men.

Hashimoto’s disease can gradually cause hypothyroidism (a lack of thyroid hormone). The symptoms might be mild or severe.

They include:

  • tiredness
  • being unable to stand the cold
  • depression
  • concentration issues
  • weight gain
  • constipation
  • muscle pain
  • dry skin
  • thin hair
  • brittle nails
  • weak or aching muscles
  • poor memory
  • enlarged thyroid
  • low libido (in men or women)

Clinical tests are used to diagnose Hashimoto’s disease and include:

Thyroid function test. This blood test tells whether your body has the right amounts of thyroid stimulating hormone (TSH) and thyroid hormone. A high level of TSH is a sign of an underactive thyroid. When the thyroid begins to fail, the pituitary gland makes more TSH to trigger the thyroid to make more thyroid hormone. When the damaged thyroid can no longer keep up, your thyroid hormone levels drop below normal.

Antibody test. This blood test tells whether you have the antibodies that suggest Hashimoto’s disease. More than one in 10 people have the antibodies but have normal thyroid function. Having only the antibodies does not cause hypothyroidism.