Explanation

A goiter is a painless lump that you might get in your neck if you have hypothyroidism. When you don't have enough thyroid hormone and your pituitary gland sends thyroid stimulating hormone (TSH) to your thyroid gland, it sometimes gets so much TSH that it becomes swollen or fat. So, a goiter is just an overgrown thyroid gland! Goiters vary in size - sometimes they can be big enough for you to see, and other times you can't see them at all, they can only be felt by a doctor.