What Are the Signs and Symptoms of Hypothyroidism?
Select from the list of symptoms and phase of hypothyroidism or scroll down the page.

• Summary List of Symptoms¹
• Early Symptoms
• Later Symptoms
• Secondary Hypothyroidism
• Symptoms in Infants and Children
• Subclinical Hypothyroidism

Early Symptoms
Many people attribute the early symptoms of hypothyroidism to stress or aging. They begin to feel chronically tired and overly sensitive to cold; muscle and joint aches often develop; modest weight gain is common even though appetite diminishes; constipation is often a problem.² Premenopausal women may experience heavy periods. ²

As your thyroid hormone levels fall over the following months, the skin becomes rough and dry, hair coarsens, and mental activity—including concentration and memory—may become slightly impaired.²

Depression can develop, and some experts believe that even mild thyroid failure can lead to major depression.^3,4

Later Symptoms
If hypothyroidism is left untreated, the classic physical changes characteristic of myxedema can develop—a round, puffy face with a sleepy appearance, dry rough skin, and loss of hair. Other later symptoms include a husky voice and numbness of the arms and legs. Muscle pain, weakness, and carpal tunnel syndrome may occur. Some people experience hearing loss, depression, mental confusion, uneasiness, daytime sleepiness, or memory problems, especially in the elderly. Obstructive sleep apnea, in which tissues in the upper airway collapse at intervals during sleep, thereby blocking the passage of air, is common. Myxedema coma is a life-threatening condition caused by long-standing hypothyroidism.²

Secondary Hypothyroidism
Secondary hypothyroidism is not common. It is caused by an abnormality of the pituitary gland and deficient TSH secretion.²

Symptoms in Infants and Children
All newborns are now screened for hypothyroidism in order to help prevent retardation, which can occur if the disorder is not detected early. Some early symptoms that develop in children who are not treated include feeding problems, constipation, hoarseness, and sleepiness. Later, babies may have protruding abdomens, rough, dry skin, and delayed teething. If they do not receive proper treatment in time, they may be extremely short for their age, have a puffy, bloated appearance, or have below-normal intelligence. Therefore, a child who appears to be growing abnormally slowly should be examined for hypothyroidism.⁵

Subclinical Hypothyroidism
Subclinical hypothyroidism, or subclinical thyroid dysfunction, is characterized by a mildly elevated TSH level with normal serum T₄ and T₃. It is called subclinical because this condition is recognized before symptoms are detected.⁶ Symptoms in adults, particularly those over age 50, usually develop so slowly that hypothyroidism is often first diagnosed in blood tests.

If you believe you may have symptoms of hypothyroidism, see a physician; only a physician can diagnose you with hypothyroidism.

1. Bellecy F. Facts from your pharmacist: A handout for patients. A patient’s guide to thyroid disease. Pharmacy Times. November 2000:57-58.
2. Hypothyroidism. In: Berkow R, ed. The Merck Manual of Diagnosis and Therapy–Volume 1 - General Medicine. 16th edition. Rahway, NJ: Merck Research Laboratories; 1992:933-935.
3. Gunnarsson T, Sjöberg S, Eriksson M, Nordin C. Depressive symptoms in hypothyroid disorder with some observations on biochemical correlates. Neuropsychobiology. 2001;43(2):70-74.
4. Rack SK, Makela EH. Hypothyroidism and depression: a therapeutic challenge. Ann Pharmacother. 2000;34(10):1142-1145.
5. Endocrinology and Metabolism. In: Isselbacher KJ, Braunwald E, Wilson JD, Martin JB, Fauci AS, Kasper DL, eds. Harrison’s Principles of Internal Medicine. 13th ed. New York, NY: McGraw-Hill, Inc.; 1994:1940.
6. The Merck Manual of Diagnosis and Therapy. 17th ed. Whitehouse Station, NJ: Merck Research Laboratories; 1999:95-96.