Common Hypothyroidism Causes
There are many things that can cause hypothyroidism. Here are some of the most common hypothyroidism causes:
Autoimmune diseases, most commonly Hashimoto's disease. This is the number one cause of hypothyroidism. In autoimmune diseases like Hashimoto's disease, the immune system attacks the thyroid, which affects the thyroid's ability to produce hormones. Hashimoto's disease sometimes causes only a thyroid goiter (swelling), but other times it causes hypothyroidism.
Surgery to remove all or part of the thyroid gland. Sometimes people need to have thyroid surgery if they have lumps on the thyroid, thyroid cancer, or Graves' disease. If the entire thyroid is removed, the person always gets hypothyroidism. If only part of the thyroid is removed, the thyroid hormones sometimes are not affected at all, or they are affected to varying degrees.
Radiation treatment. Sometimes people with thyroid lumps, thyroid cancer, cancer of the head or neck, Hodgkin's disease, lymphoma, or Graves' disease need radiation treatment. This can cause total or partial loss of thyroid function.
Hyperthyroidism treatment. Sometimes people with hyperthyroidism (thyroid gland makes too much of the hormone thyroxine) are treated with radioactive iodine or anti-thyroid medications. These treatments sometimes result in hypothyroidism.
Certain medications. Medications like lithium (used to treat psychiatric disorders) and Sulfonamides (used to treat diabetes) can cause the thyroid to make less thyroid hormone, resulting in hypothyroidism.
Less common causes of hypothyroidism include congenital disease (defective thyroid gland or no thyroid gland at birth), disorder of the pituitary gland (pea-sized gland located in the brain), iodine deficiency, and others.
Hypothyroidism risk factors
Even though hypothyroidism can affect anyone, certain people have a greater risk of developing it. Here are some risk factors for developing hypothyroidism:
If you are a woman
Having a close relative with thyroid disease
Having an autoimmune disease such as type 1 diabetes or rheumatoid arthritis
The only way to know for sure if you have hypothyroidism is to see your doctor for a
1. American Thyroid Association.
ATA Hypothyroidism Booklet. Falls Church, VA: American Thyroid Association; 2003.