Hashimoto's Disease occurs when the body's immune system attacks the thyroid gland, causing chronic inflammation. This swelling can lead to hypothyroidism, a condition in which the thyroid gland does not produce enough hormones to help carry out many bodily functions. The thyroid produces two hormones, triiodothyronine and thyroxine, which are carried through the bloodstream and affect weight, metabolism, skin moisture levels, breathing, brain development, menstruation, cholesterol, muscle strength and other essential functions.

When there is not enough of these hormones, an individual can experience fatigue, hair thinning, weight gain, constipation, depression, joint and muscle pain, heavy menstrual cycles, cold intolerance and slowed heart rate. People who have Hashimoto's disease alone may not exhibit any outward symptoms initially, however, the inflammation of the thyroid can make the throat appear swollen.