Hashimoto's disease, also known as Hashimoto's thyroiditis, is an autoimmune disorder in which the immune system attacks the thyroid gland, leading to inflammation and damage to the thyroid tissue. This can ultimately result in an underactive thyroid gland (hypothyroidism), which means the thyroid gland is not producing enough hormones for the body's needs.

Hashimoto's disease is the most common cause of hypothyroidism in the United States, especially in women over the age of 60. The exact cause of Hashimoto's disease is not known, but it is believed to be a combination of genetic and environmental factors.

Symptoms of Hashimoto's disease can be vague and may develop slowly over time. They can include fatigue, weight gain, constipation, dry skin, sensitivity to cold, joint and muscle pain, depression, and difficulty concentrating. If left untreated, Hashimoto's disease can lead to serious complications such as heart problems, goiter, and myxedema coma.

Hashimoto's disease can be diagnosed through blood tests to check thyroid hormone levels and antibodies, as well as a physical exam and medical history review. Treatment typically involves taking thyroid hormone replacement medication to bring thyroid hormone levels back to normal. Regular monitoring by a healthcare provider is necessary to ensure that the medication dosage is appropriate and to monitor for any potential complications.