Thyroid Test Results : TSH, FT3 and FT4 for Graves’ Disease and Hyperthyroidism
by Svetla Bankova
If you just left the doctor’s office with a piece of paper in your hand, given by your doctor with the following words “Your tests are abnormal– you may have Graves’ Disease or Hyperthyroidism– you probably have a lot of questions in your head. No more explanations. Doctors don’t have time to explain what are normal, what are abnormal thyroid test levels (TSH, FT3, FT4)- just because they have scheduled about 15 to 20 patients per day and they can not afford any extra time for you and your health problems.
It’s the Health Care system fault, not the doctors!
Next patient in line please..
I personally can understand your frustration, you helplessness and your despair. Because I have been there and I felt exactly the same way. I started to look for more information everywhere to find out what is a “normal thyroid levels” and how do I achieve this “normal thyroid test results”- because I wanted to feel better, healthy and without Graves’ disease or Hyperthyroidism.
I’ll try to present in a few sentences what you should be looking for, when you have been diagnosed with Graves’ Disease or Hyperthyroidism.
Perhaps one of the most confusing issues for patients today is the issue of the changing “normal” reference range for the TSH – thyroid stimulating hormone – test, which is used by most conventional practitioners to detect and monitor thyroid problems.
Thyroid Test results and Thyroid Stimulating Hormone (TSH FT3 FT4) testing is used to:
- diagnose a thyroid disorder in a person with symptoms,
- screen newborns for an under-active thyroid, or over active thyroid respectively
- monitor thyroid replacement therapy in people with hypothyroidism
- diagnose and monitor female infertility problems,
- help evaluate the function of the pituitary gland (occasionally), and
- screen adults for hyperthyroid/hypothyroid disorders as recommended by some organizations, such as the American Thyroid Association.
In late 2002, the National Academy of Clinical Biochemistry (NACB) issued new guidelines for the diagnosis and monitoring of hyperthyroid disease. In the guidelines, the NACB reported that the current TSH reference range, which usually runs from approximately 0.5 to 5.5 — may be too wide and actually may include people with thyroid disease. When more sensitive screening was done, which excluded people with thyroid disease, 95 percent of the population tested actually had a TSH level between 0.4 and 2.5. Accordingly, the new TSH ranges were adjusted.
The thyroid test results, read as normal levels should be as follows; however different laboratories have different ways of measuring. Consult your doctor for a better understanding of your thyroid tests. Blood tests to measure TSH, T4 and T3are readily available and widely used. The best way to initially test thyroid function is to measure the TSH level in a blood sample.
| TSH = 0.3-3.0 | mIU/L (mU/L) |
| FT3 = 230-420 | pg/d |
| FT4 = 0.8-1.5 | ng/dl |
| T3= 70-180 | ng/dL |
| T4 = 5.6-13.7 | ug/dL |
Again, check with your laboratory, since their measuring units may differ from the above.
I believe that once your symptoms are under control and your test are in normal range your eyes will start to improve. So besides treating the symptoms I would recommend treating the cause of Graves’ Disease as well.
Understanding your Thyroid Test Results:
A high TSH level indicates that the thyroid gland is failing because of a problem that is directly affecting the thyroid (primary hypothyroidism). The opposite situation, in which the TSH level is low, usually indicates that the person has an overactive thyroid that is producing too much thyroid hormone (hyperthyroidism). Occasionally, a low TSH may result from an abnormality in the pituitary gland, which prevents it from making enough TSH to stimulate the thyroid (secondary hypothyroidism). In most healthy individuals, a normal TSH value means that the thyroid is functioning normally.
T4 Tests
Individuals who have hyperthyroidism will have an elevated FT4, whereas patients with hypothyroidism will have a low level of FT4. Combining the TSH test with the FT4 accurately determines how the thyroid gland is functioning.
The finding of an elevated TSH and low FT4 indicates primary hypothyroidism due to disease in the thyroid gland. A low TSH and low FT4 indicate hypothyroidism due to a problem involving the pituitary gland. A low TSH with an elevated FT4 is found in individuals who have hyperthyroidism.
T3 tests are often useful to diagnosis hyperthyroidism or to determine the severity of the hyperthyroidism. Patients who are hyperthyroid will have an elevated T3 level. In some individuals with a low TSH, only the T3 is elevated and the FT4 is normal. T3 testing rarely is helpful in the hypothyroid patient, since it is the last test to become abnormal. Patients can be severely hypothyroid with a high TSH and low FT4 but have a normal T3.
| TSH mIU/L (mU/L) | T4 ug/dL | T3 ng/dL | Interpretation |
| High (> 3.0) | Normal (5.6-13.7) | Normal (70-180) | Mild (subclinical) hypothyroidism |
| High (>3.0) | Low (<5.6) | Low or normal (70-180) or < 70 | Hypothyroidism |
| Low (<0.3) | Normal (5.6-13.7) | Normal (70-180) | Mild (subclinical) hyperthyroidism |
| Low(<0.3) | High or normal (5.6-13.7), or >13.7 | High or normal (70-180) or >180 | Hyperthyroidism |
| Low(<0.3) | Low or normal5.6-13.7, or < 5.6 | Low or normal (70-180) or <70 | Rare pituitary (secondary) hypothyroidism |
If you want more information about your Thyroid Antibodies, check here: