Normal tsh levels by age

Are you sure the patient has age-related changes in thyroid function? The thyroid gland plays an important role in the readjustment of the hormonal milieu that occurs with aging. Although aging euthyroid patients have thyrotropin and thyroid hormone parameters which are substantially within the normal ranges of adults, changes in thyroid hormone production, metabolism and action occur during the aging processes. Thyroid disorders (especially subclinical thyroid dysfunction) are common in the elderly. However, the clinical manifestations may be different from those observed in younger patients. Moreover, aging patients are frequently characterized by comorbidities that may represent confounding factors in the correct diagnosis of thyroid disease, the estimation of their clinical consequences, and the approach to their treatment. Potential confounders of thyroid function tests in the elderly Acute and chronic illnesses, as well as malnutrition, may be associated with decreased levels of serum triiodothyronine (T3) and free T3 (and sometimes thyroid stimulating hormone, TSH) without concomitant thyroid disease. Also, use of certain medications common to the elderly may interfere with thyroid function tests. Some drugs may induce hyperthyroidism or hypothyroidism (i.e. amiodarone, lithium). Others may cause abnormal thyroid function tests by interfering with T4 to T3 conversion ( i.e. glucocorticoids, beta-blockers, amiodarone), decreasing TSH secretion (i.e. glucocorticoids, ...

WHAT IS THE THYROID GLAND? The thyroid gland is a butterfly-shaped endocrine gland that is located in the lower front of the neck, just above the collarbone. The thyroid’s job is to make thyroid hormones, which are released into the blood and then carried to every tissue in the body. In children, thyroid hormone helps to ensure that growth and development occur normally and that the body’s energy, metabolism, heart, muscles, and other organs are working properly. HOW DOES THE THYROID GLAND FUNCTION? The major thyroid hormone secreted by the thyroid gland is levothyroxine, (also called T4 because it contains four iodine atoms). The active form of thyroid hormone is tri-iodothyronine (T3) which is converted from T4. This conversion happens outside of the thyroid gland and still occurs normally in people who have thyroid disease or do not have a thyroid gland. It is very important for a healthy body that the amount of thyroid hormone in the bloodstream is just right: not too high and not too low. The pituitary gland is in the brain and sends a message to the thyroid gland called Thyroid Stimulating Hormone (TSH), which stimulates the thyroid to produce T4. If the level of circulating thyroid hormone drops, the pituitary releases more TSH to push the thyroid gland to make more hormone. If there is too much thyroid hormone in the blood, the pituitary decreases TSH to slow down the thyroid. In this way, the pituitary gland regulates how much thyroid hormone is produced to keep i...

The normal range for thyroid-stimulating hormone (TSH) is 0.35 to 4.5 milli-international units per liter (mIU/l) of blood. TSH is a hormone produced by your pituitary gland that regulates the production of hormones by your thyroid gland. The levels of TSH in your body can tell you how well your thyroid gland is functioning. A variety of factors can cause atypical TSH levels, such as thyroid disease, the effects of certain medications, autoimmune conditions, and more. Read on to learn more about normal TSH levels and the symptoms, tests, and treatments associated with unusual TSH levels. How do doctors measure TSH levels? Your doctor can order Tests that your doctor can use to confirm unusual TSH levels include the following: • A T 4 test will show the levels of T 4 in your system. T 4 is one of the two main thyroid hormones. If your T 4 level is too high, it might indicate hyperthyroidism. If your T 4 level is too low, it could indicate hypothyroidism. • A T 3 test can help doctors further understand the results of your T 4 test. T 3 is the other main thyroid hormone. If your T 4 level is typical but your doctor still suspects that you might have hyperthyroidism, the T 3 test can help confirm the diagnosis. T 3 is high in hyperthyroidism. What should I do about an unusual TSH test result? If your TSH levels are outside the normal range, your doctor will discuss possible causes. They may ask about your family history and any health symptoms you are experiencing. Tell your ...

ABSTRACT Subclinical hypothyroidism is defined by an elevated serum thyroid-stimulating hormone (TSH) level along with a normal free thyroxine (T 4) level. Whether it should be treated remains controversial. Currently, the best practical approach is to base treatment decisions on the degree of TSH elevation, thyroid autoimmunity, and associated comorbidities. KEY POINTS • From 4% to 20% of adults have subclinical hypothyroidism, with a higher prevalence in women, older people, and those with thyroid autoimmunity. • Subclinical hypothyroidism can progress to overt hypothyroidism, especially if antithyroid antibodies are present, and has been associated with adverse metabolic, cardiovascular, reproductive, maternal-fetal, neuromuscular, and cognitive abnormalities and lower quality of life. • Some studies have suggested that levothyroxine therapy is beneficial, but others have not, possibly owing to variability in study designs, sample sizes, and patient populations. • Further trials are needed to clearly demonstrate the clinical impact of subclinical hypothyroidism and the effect of levothyroxine therapy. W hether subclinical hypothyroidism is clinically important and should be treated remains controversial. Studies have differed in their findings, and although most have found this condition to be associated with a variety of adverse outcomes, large randomized controlled trials are needed to clearly demonstrate its clinical impact in various age groups and the benefit of le...