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Simple Nontoxic Goiter

(Euthyroid Goiter)


Laura Boucai

, MD, Weill Cornell Medical College

Reviewed/Revised Feb 2024

Simple nontoxic goiter, which may be diffuse or nodular, is noncancerous hypertrophy of the thyroid gland without hyperthyroidism, hypothyroidism, or inflammation. Except in severe iodine deficiency, thyroid function is normal and patients are asymptomatic except for an obviously enlarged, nontender thyroid. Diagnosis is clinical and with determination of normal thyroid function. Treatment is directed at the cause, but partial surgical removal may be required for very large goiters.

Simple nontoxic goiter, the most common type of thyroid enlargement, is frequently noted at puberty, during pregnancy, and at menopause. The cause at these times is usually unclear. Known causes include

  • Intrinsic thyroid hormone production defects

  • Ingestion of foods that contain substances that inhibit thyroid hormone synthesis (goitrogens, eg, cassava, broccoli, cauliflower, cabbage), as may occur in countries in which iodine deficiency is common

  • Medications that can decrease the synthesis of thyroid hormone (eg, amiodarone or other iodine-containing compounds, lithium)

Iodine deficiency Iodine Deficiency In the body, iodine (I) is involved primarily in the synthesis of 2 thyroid hormones, thyroxine (T4) and triiodothyronine (T3). Iodine occurs in the environment and in the diet primarily as... read more is rare in North America but remains the most common cause of goiter worldwide (termed endemic goiter). Compensatory small elevations in thyroid-stimulating hormone (TSH) occur, preventing hypothyroidism Hypothyroidism Hypothyroidism is thyroid hormone deficiency. Symptoms include cold intolerance, fatigue, and weight gain. Signs may include a typical facial appearance, hoarse slow speech, and dry skin. Diagnosis... read more Hypothyroidism , but the TSH stimulation results in goiter formation. Recurrent cycles of stimulation and involution may result in nontoxic nodular goiters. However, the true etiology of most nontoxic goiters in iodine-sufficient areas is unknown.

Symptoms and Signs of Simple Nontoxic Goiter

Patients with goiter are usually asymptomatic. Those with larger goiters may present with a dysphagia, hoarseness, or a sensation of fullness in the throat (globus pharyngis) (1 Symptoms and signs reference Simple nontoxic goiter, which may be diffuse or nodular, is noncancerous hypertrophy of the thyroid gland without hyperthyroidism, hypothyroidism, or inflammation. Except in severe iodine deficiency... read more ). The patient may have a history of low iodine intake or overingestion of food goitrogens, but these phenomena are rare in North America.

In the early stages, the goiter is typically soft, symmetric, and smooth. Later, multiple nodules and cysts may develop.

Symptoms and signs reference

  • 1. Sajisevi M, Caulley L, Eskander A, et al. Evaluating the Rising Incidence of Thyroid Cancer and Thyroid Nodule Detection Modes: A Multinational, Multi-institutional Analysis. JAMA Otolaryngol Head Neck Surg 2022;148(9):811-818. doi:10.1001/jamaoto.2022.1743

Diagnosis of Simple Nontoxic Goiter

  • Thyroidal radioactive iodine uptake

  • Thyroid scan

  • Thyroid ultrasonography

  • Thyroxine (T4), triiodothyronine (T3), and thyroid-stimulating hormone (TSH) levels

In endemic goiter, serum TSH may be slightly elevated, and serum T4 may be low-normal or slightly low, but serum T3 is usually normal or slightly elevated.

Treatment of Simple Nontoxic Goiter

  • Depends on cause

In iodine-deficient areas, eliminate iodine deficiency by these means:

  • Iodine supplementation of salt

  • Oral administration of iodized oil

  • Intramuscular administration of iodized oil yearly

  • Iodination of water, crops, or animal fodder

Any goitrogens (eg, cassava, broccoli, cauliflower, cabbage) being ingested should be stopped.

In other instances, suppression of the hypothalamic-pituitary axis with thyroid hormone blocks thyroid-stimulating hormone (TSH) production (and hence stimulation of the thyroid).

Moderate doses of levothyroxine (100 to 150 mcg orally once a day depending on the serum TSH) are useful in younger patients to reduce the serum TSH to the low-normal range. Levothyroxine is contraindicated in older patients with nontoxic nodular goiter because these goiters rarely shrink and may harbor areas of autonomy, so that levothyroxine therapy can result in hyperthyroidism Hyperthyroidism Hyperthyroidism is characterized by hypermetabolism and elevated serum levels of free thyroid hormones. Symptoms include palpitations, fatigue, weight loss, heat intolerance, anxiety, and tremor... read more Hyperthyroidism .

Large goiters occasionally require surgery to shrink the gland enough to prevent interference with respiration or swallowing or to correct cosmetic problems.

Treatment with iodine-131 for large goiters is generally ineffective unless there is clear evidence of autonomous function manifested by a suppressed TSH.

Key Points

  • Thyroid function is usually normal.

  • When the cause is iodine deficiency, iodine supplementation is effective treatment.

  • Blocking thyroid-stimulating hormone production by giving levothyroxine is useful in younger patients to halt stimulation of the thyroid and shrink the goiter.

  • Surgery may be needed for large goiters.

Drugs Mentioned In This Article

Drug Name Select Trade
Cordarone, Nexterone, Pacerone
Eskalith, Eskalith CR, Lithobid
Ermeza, Estre , Euthyrox, Levo-T, Levothroid, Levoxyl, Synthroid, Thyquidity, Thyro-Tabs, TIROSINT, TIROSINT-SOL, Unithroid
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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