Hypothyroidism is a condition in which the thyroid gland does not produce enough hormones for the body to function normally. It can affect people of any age, including children and infants. In children, hypothyroidism may be present at birth or may develop later in childhood.

When you have Hashimoto's disease, your immune system attacks and damages your thyroid gland. If left untreated, the disease can progress to hypothyroidism and greatly affect your body's functions due to insufficient thyroid hormone supply.