Why does thyroid enlarge

A range of iodine supplements are also available in health stores. Medical professionals reserve active treatment of goiters for cases that cause symptoms. If the goiter is small and thyroid function is normal, people do not typically need treatment.

In cases caused by an underactive thyroid, or hypothyroidism, treatment is a synthetic replacement of thyroid hormone. In goiters caused by an overactive thyroid, or hyperthyroidism, treatment aims to counter the excess hormone production.

For instance, antithyroid drugs, such as thionamide drugs, gradually reduce excessive hormone levels. Doctors will reserve surgery to reduce the size of the swelling for cases where the goiter is causing troublesome symptoms, such as difficulty breathing or swallowing.

Surgeons will usually perform thyroidectomies , the removal of part or all of the thyroid gland, when the person is under general anesthetic. A healthcare professional may diagnose a goiter through a physical examination of the neck, palpating for swelling. They may ask the person to swallow while feeling for a goiter. If they suspect a goiter, they may recommend further tests to determine any underlying problems with thyroid function, such as hyperthyroidism or hypothyroidism.

Thyroid function tests are blood tests that measure levels of thyroid-stimulating hormone TSH and thyroxine. A carefully controlled feedback mechanism means that TSH stimulates the thyroid to produce more thyroxine, while T4 tells the thyroid to stop producing as much thyroxine. With an overactive thyroid, TSH levels are low or non-existent, and T4 levels are high. In people with underactive thyroid, the reverse is true.

TSH levels are high and T4 levels are low. A goiter is a swelling of the thyroid gland. It is often harmless, though it can signal an underlying thyroid condition. To compensate for the hormone deficiency, the thyroid gland is stimulated in its growth, forms new gland cells and enlarges. On average, the thyroid gland has a normal volume of up to 18 ml.

We speak of an enlarged thyroid gland when its total volume exceeds 25 ml in men and 18 ml in women. Enlargement may affect the whole tissue or may originate from single or multiple nodes in the thyroid gland. In addition to the sheer increase in size or nodular change, there are also often accompanying dysfunctions.

Scintigraphy — an examination in which weakly radioactive iodine is administered into the veins — reveals the ability to form hormones. As a rule, these are benign changes. However, if they produce too much thyroid hormone, they must be removed to prevent overactive thyroid. Warm nodes are always benign. It is suspected that these are malignant cells. Hypothyroidism and thyroiditis. Williams Textbook of Endocrinology. Philadelphia, PA: Elsevier; chap Multinodular goiter. Endocrinology: Adult and Pediatric.

Philadelphia, PA: Elsevier Saunders; chap Jonklaas J, Cooper DS. Goldman-Cecil Medicine. In: Kliegman RM, St. Nelson Textbook of Pediatrics. URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. Learn more about A. The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed physician should be consulted for diagnosis and treatment of any and all medical conditions.

Call for all medical emergencies. A goiter may be associated with no change in thyroid function or with an increase or decrease in thyroid hormones. The most common cause of goiters worldwide is a lack of iodine in the diet.

In the United States, where the use of iodized salt is common, goiters are caused by conditions that change thyroid function or factors that affect thyroid growth. Treatment depends on the cause of the goiter, symptoms, and complications resulting from the goiter. Small goiters that aren't noticeable and don't cause problems usually don't need treatment.

Most people with goiters have no signs or symptoms other than a swelling at the base of the neck. In many cases, the goiter is small enough that it's only discovered during a routine medical exam or an imaging test for another condition.

Other signs or symptoms depend on whether thyroid function changes, how quickly the goiter grows and whether it obstructs breathing. The size or position of a goiter may obstruct the airway and voice box. Signs and symptoms may include:. The pituitary gland and the hypothalamus are located within the brain and control hormone production. Two hormones produced by the thyroid are thyroxine T-4 and triiodothyronine T When the thyroid releases T-4 and T-3 into the bloodstream, they play a role in many functions in the body, including the regulation of:.

The thyroid gland also produces calcitonin, a hormone that helps regulate the amount of calcium in the blood. The pituitary gland and hypothalamus control the rate at which T-4 and T-3 are produced and released. The hypothalamus is a specialized region at the base of the brain. It acts as a thermostat for maintaining balance in multiple body systems.

The hypothalamus signals the pituitary gland to make a hormone known as thyroid-stimulating hormone TSH. The pituitary gland — located below the hypothalamus — releases a certain amount of TSH , depending on how much T-4 and T-3 are in the blood.