Autoimmune Diseases: The most common cause of this is when the body’s immune system mistakenly attacks the thyroid gland.
Hashimoto’s Thyroiditis: Causes hypothyroidism.
Graves’ Disease: Causes hyperthyroidism.
Iodine Deficiency: The body needs iodine to produce thyroid hormone. Too little or too much iodine in the diet can cause problems.
Genetics: If your parents or siblings have thyroid problems in your family, you are more likely to develop them.
Hormonal Changes: During pregnancy and after childbirth, women experience major changes in hormones that can affect the thyroid gland.
Side Effects of Medications: Long-term use of certain medications, such as lithium, can disrupt thyroid function.
Radiation to the neck: People who have had radiation to the neck as part of cancer treatment may experience thyroid dysfunction.
Thyroid Nodules: Tumors in the thyroid gland can sometimes cause excessive hormone production.
