That's a pretty wide reference range. Usually the average person says 1.0 to 2.0 max.
And symptoms play a huge role with that lab.
it means you are hypothyroid,i e have higher than normal levels of thyroid stimulating hormone as your body needs a bigger stimulus to produce t3 &t4 hormones.it can be corrected by taking adequate doses of levothyroxine as prescribed by an endocrinologist.the normal range of tsh is approx. 1---4.5
I guess that would all depend on you too.
Are you feeling bad?
Most likely the problem is Hashimoto's Disease. It is the most common cause of being hypothyroid, like your TSH indicates. In order to be sure you really need additional testing for thyroid antibodies, TPO ab and TG ab. Also you need to know the levels of the actual, biologically active thyroid hormones, which are free T3 and free T4 (note that these are not the same as total T3 and total T4).
You should request these tests and if the doctor resists, then you should insist on it and not take no for an answer. When you get these tests done and the lab report is available, then get a copy and post results and reference ranges shown for each test and members will be glad to help interpret and advise further.
Also, do you have symptoms of being hypothyroid?