Normal TSH Levels

Thyroid stimulating hormone, or TSH is the hormone that stimulates the thyroid gland into secreting the thyroid hormones. TSH or thyroid stimulating hormone is formed by the pituitary gland, which is the main gland of the endocrine system and at the base of the brain. One can know the normal level of TSH from a blood test.

The pituitary gland tells the thyroid gland, to create and release the hormone triiodothyronine which is more known as T3, and thyroxine hormone which is more known as T4.

Here is a data to help you understand TSH levels in women and men which are considered to be normal; and the levels of under and over secretion.

• Normal TSH Levels - 0.4 - 4.0 mIU/L
• Underactive Thyroid - 2.0 mIU/L or more
• Thyroid Disorder - 0.5 and 3.0 mIU/L

As the thyroid problems show similar symptoms of pregnancy, it is difficult to diagnose the normal level of TSH in pregnancy. Also, the normal range for adults, children and newborns is different. The above chart shows the various levels for adults.

However, for children the normal levels are 0.7 - 6.4 mIU/L and for newborns is 1 - 39 mIU/L.

This test is suggested by the doctor if a person is showing any signs of abnormal thyroid functions. Such thyroid problems are hyperthyroidism or hypothyroidism. Here is some important information about the TSH test, which will help you prepare for the test.

Preparing for the TSH Test
Certain medications can alter the TSH measurements, such drugs include amiodarone, antithyroid medications, dopamine, lithium, potassium iodide and prednisone. The health care provider will ask you to stop taking such drugs before the test to get the TSH measurements right.

Also, if you had any test in which you were given any radioactive materials then inform your doctor, for example if you had X-rays test which involved use of iodine dye. The test results can also be affected by severe stress or by any long-term chronic disorder. Make sure your doctor is aware of any such issues.

Procedure of the TSH Test
An elastic band is used on the upper arm to apply pressure to the body area, so that the vein swells with blood. The body area from which the blood is collected is cleaned with antiseptic. The blood is removed using a needle from the elbow or the back of the hand, and the punctured skin is covered to stop any bleeding.

The blood sample is collected in a vial or tube. To check normal TSH in children or infants, a sharp tool lancet is used to make the body part bleed, from which the sample is collected. The results of the test are available within 3-4 days.

A person can feel the needle as a prick, and some might feel moderate pain. After the blood test is done, a person usually experiences throbbing in the punctured area. In few cases, a person experiences feeling of light-headedness or fainting, and sometimes skin infection of the punctured skin.

If a person is not showing normal TSH, but abnormal or low TSH levels which means the person is suffering from certain disorder.

High TSH levels

• It means the person has primary hypothyroidism.
• The person is going through TSH-dependent hyperthyroidism.
• The patient has resistance of thyroid hormone.
• A person having exposure of mice can also show above normal TSH. Such persons commonly are lab workers or vet doctors.
• Cretinism is also a sign of above normal TSH level.

Low TSH levels

• This means that the person has hyperthyroidism.
• There is deficiency of thyroid stimulating hormone in the body.
• Person using certain medications like glucocorticoids, bexarotene and dopamine agonists can also show the lower than normal TSH.

The treatment for thyroid stimulating hormone related disorder differs from person to person. This is because, the above mentioned values for normal levels of TSH are just a reference. The range for normal TSH can change from lab to lab. Hence, after your test result the doctor will give you a treatment suited for your condition, which will help you achieve the normal TSH level.