An elevated TSH in the presence of normal levels of T4 and T3 is suggestive of subclinical hypothyroidism, which is treated with L-thyroxine, explains The Merck Manual Professional Edition. Patients with this condition have an increase in the risk for developing overt hypothyroidism, states the American Academy of Family Physicians.
Subclinical hypothyroidism is a state in which the pituitary gland produces extra TSH in order to maintain an adequate production of thyroid hormone by the thyroid gland, explains MedicineNet.com. It is subclinical because most patients do not exhibit symptoms. Some patients with symptoms experience mild fatigue, cold intolerance, weight gain, depression and memory problems, according to WebMD.
Subclinical hypothyroidism is common and occurs in 15 percent of elderly women and 10 percent of elderly men, explains The Merck Manual Professional Edition. Patients with a TSH that is greater than 10 milliunits per liter are likely to develop hypothyroidism within 10 years of the finding, and are also likely to have hypercholesterolemia and atherosclerosis.
Risk factors for developing subclinical hypothyroidism include Hashimoto's thyroiditis, recent pregnancy and delivery, explains The Journal of the American Medical Association. Other risk factors include recent treatment with interferon alfa, interleukin 2, amiodarone, or lithium. Patients treated with radioactive iodine for hyperthyroidism also have an increase in the risk for developing this condition.