Patients who have their complete thyroid gland removed no longer produce the thyroid hormone, according to Mayo Clinic. Unless they take a synthetic version of the hormone, they develop hypothyroidism. There is also the possibility of nerve damage, leading to a permanent hoarse or weak voice.
The thyroid gland is in the front of the neck. The gland controls the body's temperature regulation, use of calories and heartbeat, according to WebMD. The thyroid hormone affects nearly every part of the body.
Surgeons may remove the thyroid due to cancer, noncancerous enlargements of the gland or an overactive thyroid, reports Mayo Clinic. Thyroid cancer is the most common reason for removal of the gland. Enlargements of the gland are goiters, and they sometimes cause difficulty breathing or lead to hyperthyroidism. Doctors treat hyperthyroidism for reasons other than goiters with radioactive iodine, but some patients with the condition prefer surgery to remove the thyroid.
Untreated hyperthyroidism leads to more severe consequences of removal of the thyroid, reports WebMD. Patients may develop heart problems and joint pain. The condition also causes infertility and weight gain. The synthetic hormone treats hyperthyroidism, but patients must take it every day for the rest of their lives as well as regular blood tests to determine if their dosage needs adjustment.