Hashimoto’s disease is the most common thyroid disorder in the United States, affecting as many as 14 million people. It’s named after the Japanese surgeon who discovered it in 1912, and is sometimes also called chronic lymphocytic thyroiditis or autoimmune thyroiditis. It’s an autoimmune disease, which means that it’s caused when something goes wrong with your immune system.

“If you have Hashimoto’s disease, your immune system mistakenly attacks your healthy thyroid gland, which is located in your neck below your Adam’s apple,” said Wynn Htun, M.D., an endocrinologist at Geisinger Wyoming Valley Medical Center in Wilkes-Barre. “When this happens, your thyroid becomes inflamed, which prevents it from making the right amount of thyroid hormone.”

If this impairment is severe enough, your thyroid won’t make enough of the hormones your body needs to function properly, leading to a condition called hypothyroidism.   

The signs and symptoms of Hashimoto’s disease

“Hashimoto’s disease is the most common cause of hypothyroidism and many of the symptoms of these two conditions are the same,” said Dr. Htun. “However, if you have Hashimoto’s disease, you may not experience any symptoms for a long time until the disease progresses.”

When you do experience symptoms, they will include:

  • Tiredness

  • Constipation

  • Increased sensitivity to cold

  • Brittle nails, dry skin and puffy face

  • Hair loss

  • Weight gain

  • Prolonged menstrual bleeding

  • Muscle aches, joint pain and tenderness

  • Mood changes such as depression

  • Memory loss

The causes and risk factors of Hashimoto’s disease

Doctors don’t know exactly why some people develop Hashimoto’s disease. Some researchers think it could be caused by exposure to bacteria or a virus, while others say that genetics may be to blame. Regardless of the cause, there are several common risk factors that many people with Hashimoto’s disease share.

“While anyone can develop the disease, women are more likely to develop Hashimoto’s disease than men,” said Dr. Htun. “It is also more likely to develop in middle age, and in people with another autoimmune disease such as lupus, rheumatoid arthritis, or type 1 diabetes.”

People who have a family member with Hashimoto’s disease are also at greater risk for developing it.

Diagnosing and treating Hashimoto’s disease

If you have any of the symptoms of Hashimoto’s disease or hypothyroidism, it’s important to see your doctor. Diagnosing the disease is relatively simple. It involves a blood test that will measure the level of thyroid hormones in your blood. Additionally, your doctor may perform another blood test to look for antibodies to a specific enzyme created by your thyroid – since Hashimoto’s disease is an autoimmune disease, it causes the production of these abnormal antibodies.

Fortunately, treatment of Hashimoto’s disease is also relatively simple. If your hormone levels are not normal, you will be prescribed a synthetic thyroid hormone to bring your hormone levels into the normal range. This treatment is usually lifelong and will require you to have your hormone levels tested, usually about once a year, to monitor your levels and make appropriate adjustments to your medication.

“When left untreated, Hashimoto’s disease can cause complications like goiter, heart problems, mental health issues and an increased risk for birth defects in children born to mothers with the disease,” said Dr. Htun. “If you’re feeling tired or more sluggish than usual, it’s important to get tested for potential problems with your thyroid.”