What is subclinical hypothyroidism

The thyroid gland itself is regulated by the hormone TSH (thyroid stimulating hormone), which is produced in the pituitary gland. If the thyroid gland is not producing enough T4, the TSH levels increase in order to stimulate the thyroid to work harder. In hypothyroidism—in which the thyroid simply cannot make enough T4—the TSH levels are almost always greatly elevated. Verywell / Emily Roberts What Is Subclinical Hypothyroidism? Subclinical hypothyroidism is the condition in which T4 levels remain in the normal range (that is, frank hypothyroidism is not present), but TSH levels are elevated: the high TSH levels are required in order to maintain that normal T4 level. So subclinical hypothyroidism implies that the thyroid gland itself is not functioning entirely normally. It's only by "whipping" the thyroid (with high TSH levels) that adequate T4 levels can be maintained. There is quite a bit of controversy today regarding the true significance of subclinical hypothyroidism. Because the T4 levels are in fact normal in this condition, in theory, subclinical hypothyroidism should not be much of a problem. But evidence suggests that subclinical hypothyroidism does produce clinical problems at least sometimes—and so, at least in some cases, it should be treated. Diagnosis This condition is diagnosed with blood tests, specifically, by measuring T4 levels and TSH levels. Subclinical hypothyroidism is present if the T4 levels are in the normal range (4 to 12 ug/dL), and the TSH le...

While screening patients for thyroid disease, physicians often find increased thyrotropin-stimulating hormone (TSH) levels in patients whose free thyroxine (T 4) levels are not below normal. This state, termed “subclinical hypothyroidism,” is most commonly an early stage of hypothyroidism. Although the condition may resolve or remain unchanged, within a few years in some patients, overt hypothyroidism develops, with low free T 4 levels as well as a raised TSH level. The likelihood that this will happen increases with greater TSH elevations and detectable antithyroid antibodies. Because patients with subclinical hypothyroidism sometimes have subtle hypothyroid symptoms and may have mild abnormalities of serum lipoproteins and cardiac function, patients with definite and persistent TSH elevation should be considered for thyroid treatment. Levothyroxine, in a dosage that maintains serum TSH levels within the normal range, is the preferred therapy in these patients. Measurement of serum TSH is generally considered the best screening test for thyroid disease; increased values usually indicate hypothyroidism, and decreased values usually indicate hyperthyroidism. This test has proved to be both sensitive and specific. Its very sensitivity, however, may create a dilemma, since some patients are found to have elevated serum TSH levels, suggesting hypothyroidism, but have normal levels of thyroid hormone, whether measured as free thyroxine (T 4) or free T 4 index. This state—an ele...

Subclinical Hypothyroidism • Care notes • • • • • • • • • • What is subclinical hypothyroidism? Subclinical hypothyroidism is a condition that develops when your thyroid stimulating hormone (TSH) level is higher than normal. TSH is made in the brain and controls how much thyroid hormones are made. Thyroid hormones help control body temperature, heart rate, growth, and weight. Subclinical hypothyroidism can lead to hypothyroidism. What causes subclinical hypothyroidism? • A family history of hypothyroidism • An autoimmune disease, such as inflammation of your thyroid, or Hashimoto disease • Surgery, radiation therapy, or medicines such as lithium, sedatives, or narcotics • Thyroid cancer or viral infection • Diabetes or other conditions that affect the pituitary, hypothalamus, or thyroid gland What are the signs and symptoms of subclinical hypothyroidism? Any of the following may develop slowly, sometimes over several years: • Exhaustion • Sensitivity to cold • Headaches or decreased concentration • Muscle aches or weakness • Constipation • Dry, flaky skin or brittle nails • Thinning hair • Heavy or irregular monthly periods • Depression or irritability How is subclinical hypothyroidism diagnosed? Your healthcare provider will ask about your symptoms and which medicines you take. Tell your provider about your medical history and if anyone in your family has hypothyroidism. A blood test will show your TSH level. How is subclinical hypothyroidism treated? Treatment depends on...