Hypothyroidism (Underactive Thyroid) and Autoimmune Diseases
How Hypothyroidism and Autoimmune Diseases are Connected
Hypothyroidism [high-poh-THIGH-roy-diz-uhm], a condition where the thyroid gland doesn't produce enough thyroid hormone, has a strong association with autoimmune diseases. This connection is one reason people may search for thyroid and autoimmune conditions together. Autoimmune diseases occur when the immune system mistakenly attacks the body's own tissues. Hashimoto’s disease (also called Hashimoto’s thyroiditis) is an autoimmune disease where the immune system attacks and damages the thyroid. As a result, the damaged thyroid may not be able to produce enough thyroid hormone.
In addition, people who have one autoimmune condition may be more likely to develop another. This means that some people with autoimmune thyroid disease, such as Hashimoto’s disease, may also have other autoimmune conditions—and some people with other autoimmune diseases may have a higher chance of developing hypothyroidism. Examples include:
- Type 1 diabetes: Type 1 diabetes is an autoimmune condition in which the immune system attacks the cells in the pancreas that make insulin. People with type 1 diabetes have a higher risk of autoimmune thyroid disease, including Hashimoto’s disease, which can lead to hypothyroidism.
- Lupus: Lupus is an autoimmune disease that can affect many parts of the body. People with lupus may be more likely to develop thyroid problems, including hypothyroidism, than people without lupus.
- Psoriasis and psoriatic arthritis: Psoriasis affects the skin, and psoriatic arthritis affects the joints. Both are immune-related conditions. Some people with psoriasis or psoriatic arthritis may have a higher chance of also having autoimmune thyroid disease, such as Hashimoto’s disease.
- Rheumatoid arthritis: Rheumatoid arthritis is an autoimmune disease that mainly affects the joints. People with rheumatoid arthritis may be more likely to have thyroid disease, including hypothyroidism, and people with autoimmune thyroid disease may also have a higher chance of developing rheumatoid arthritis.
It’s important to remember that having hypothyroidism does not mean you will develop another autoimmune condition. However, autoimmune thyroid disease and other autoimmune diseases can sometimes occur together. If you have hypothyroidism and develop new or ongoing symptoms, talk with a healthcare professional. They can help determine whether additional testing is needed and recommend the right treatment for you.