high TSH normal T3/T4

On a recent blood test, my TSH was over 8 but the T3/T4 levels were normal. What could cause this?

[AR-10]

Laboratory limits that are too broad.

By the time your Free T3 goes below lab limit, you are extremely ill.

It's possible the TSH result could be a lab error, but it's more likely your thyroid hormone levels are not optimal.

[Shiwali]

At the age of 35 yrs, having T3 and T4 within normal limits, T3 65 ng/dl and T4 1.00  but TSH value shockingly shows >150 during a routine checkup, with no apparent symptoms/reasons. Anything to get concerned about?

[Super_sally888]

Vicky,
If your TSH level is 8 it means you have hypothyroid.  Your thryoid is struggling to give you the hormones you need.  You should be treated with thyroid hormone to bring your TSH level down to around 2 or a little lower.

Shiwali,
Your test needs to be repeated to see if this result is a lab error or if you get it again with further testing.

If the TSH is indeed this high, it is quite amazing that you don't have symptoms.  However, it does mean that your thyroid is having a very hard time maintaining the required levels.  If your thyroid conks out completely and can no longer make the thyroid hormones (likely) you are going to be very unwell and will definitely have symptoms.  Your doctor should test for thyroid antibodies to see what is happening and also you should be treated with thryoid hormone to bring the levels down.

You should be seen by an endocrinologist for further evaluation and treatment.

Sally