Hi Denzy
I had half my thyroid removed 12 years ago due to suspicious cysts, before the op the blood tests returned normal and after I was told that half a thyroid can easily do the job of a whole one. Over the years I have had odd symptoms but blood results have always come back "normal". As others have said, there is a huge "normal" range but GP's have to stick to it and there seems to be no room to consider other symptoms specific to the person.
My worst problem, apart from aching in the thyroid which is due to more cysts, is mood swings - I can become quite irrational for about a month at a time, full of gloom and doom and tearful, then gradually (thank heavens) I begin to feel more optimistic and my normal cheerful self. My monthly cycle is also becoming unpredictable, although that may be the M-word...