1) Hypothyroidism is a treatable condition in which the thyroid gland does not produce enough of the hormones called thyroxine (T4) and triiodothyronine (T3). Though people of any age can get this condition, adults over the age of 50, particularly women, have the highest risk.
2) The thyroid gland is a small, two-lobed gland located in the front of the neck, below the larynx. One lobe is located on each side of the trachea and is connected by tissue called the isthmus. The thyroid gland produces hormones which are involved in regulating metabolism and calcium balance.
3) The most common cause of an underactive thyroid gland is an autoimmune response. The body produces antibodies against the thyroid gland, as if it were a foreign or threatening organism. Hashimoto’s syndrome, also called chronic thyroiditis, is an autoimmune disorder in which inflammation causes reduced thyroid function.
4) Some women develop postpartum thyroiditis within the first year following delivery. The painless inflammation of the thyroid gland can last from several weeks to several months. In some cases, this condition leads to long-term hypothyroidism.
5) Radiation therapy used to treat head and neck cancers, radioactive iodine used to treat an overactive thyroid gland, partial or complete surgical removal of the thyroid gland and certain medications, such as lithium, contribute to hypothyroidism. In rare cases, congenital hypothyroidism, which is the absence of a thyroid gland or presence of a defective thyroid gland at birth, a pituitary gland disorder, and an iodine deficiency lead to hypothyroidism.
6) Generally, the symptoms develop slowly. Early signs include fatigue, increased sensitivity to cold, constipation, unintentional weight gain, pale, dry skin, thin, brittle hair and fingernails, heavier menstrual periods, joint and muscle pain and depression. Left untreated, thinning of the eyebrows and skin develops, the senses of taste and smell decrease, the voice becomes hoarse, speech slows and the face, hands and feet become puffy.
7) A highly sensitive blood test to measure TSH , which is thyroid stimulating hormone produced by the pituitary gland, is used by physicians to detect thyroid disorders, often before symptoms present. A laboratory test to measure T4, which is the hormone thyroxine produced by the thyroid gland, is done to confirm the diagnosis.
8) Daily use of levothyroxine, which is a synthetic thyroid hormone, is the standard treatment. It restores adequate thyroid hormone levels. Treatment is usually lifelong, though dosage may be modified depending upon TSH levels. TSH levels are often checked two to three months after starting treatment followed by annual monitoring.
PubMed Health: Hypothyroidism
University of Maryland Medical Center: Endocrinology Health Guide/ The Thyroid Gland
University of Maryland Medical Center: Endocrinology Health Guide/ Hypothyroidism
PubMed Health: Chronic Thyroiditis (Hashimoto’s Disease)
Mayo Clinic: How Long Does Postpartum Thyroiditis Usually Last?
Mayo Clinic: Hypothyroidism (Underactive Thyroid) Causes
MedlinePlus: TSH Test
Mayo Clinic: Hypothyroidism (Underactive Thyroid) Treatment and Drugs
Reviewed August 15, 2011
by Michele Blacksberg R.N.
Edited by Jody Smith