subclinical hyperthyroidism?

[kamikazee]

Hello I have been suffering from a number of symptoms for years. For the longest time they seemed like they where all gi related, but now I'm not sure. I have had almost every test possible on the digestive tract, such as food intolerances, colonscopy, endoscopy pretty much everything. And everything comes back clean the only diagnosis I received is rapid gastric emptying. Which doesn't make any sense because I never have had any kind of stomach surgery and that seems to be the main if only cause of it. I came across somebody who had similar symptoms and found it to be caused by hyperthyroidism.
So after looking at some past test results I came across my thyroid results that where done about 6 months ago;
Test results:

TSH Value = 0.67 Range = 0.40 - 4.50

T4 Free Value = 1.2 Range = 0.8 - 1.8

When the doctor did this test she told me that the results where normal, but after looking at it I wonder if the TSH level is a little low? I read online that ideally TSH should be around 2.0? Is this correct? So is this possibility indicating evidence of hyperthyroidism? Because with some of the symptoms I am currently having it would make a lot of sense.

Symptoms:
Chronic Daily Diarrhea
Abdominal Cramps
Excessive Flatulence
Nausea
Chest Tightness
Shortness of breath
Anxiety
Jittery/Nervous
Heat Intolerance(I'm not sure about this one all I know is I feel uncomfortable when I get hot)
Extreme Fatigue(very hard to awake in morning)
Hard to focus eyes(This is probably the most troubling one its very hard to focus my eyes and I feel like I can't concentrate)
Blurry Vision
Hard to concentrate
Poor Memory
Insomnia(on average takes 3 hrs or more to fall asleep at night also have been checked for every sleeping problem possible absolutely nothing found)

I also want to make a note that for the longest time doctors blamed it all on my diet saying its either to much caffeine or to much fast food. So in an attempt to prove them wrong I did a cave many diet for 2 months. Meaning I only drank water and wholesome food. Which means I ate chicken, fish, no red meats, vegetables, fruits, and water. No seasonings, no butter, only bland and my symptoms didn't change. I thought for sure I would sleep like a baby because of having no caffeine didn't change my insomnia at all or my diarrhea. My parents where stumped as was I. Please Help! This has been going on for 5+ years. I just feel sick and uncomfortable every day.

[goolarra]

I know you want a definitive answer.  All you can do is chip away at the possibilities by eliminating one after the other.

Best of luck with your doctor.  

[kamikazee]

Ok thanks I am due to see my doctor soon for medication refills. I will ask for these tests. I just wish I could find a definitive answer to these symptoms. No she didn't check Free T3 I just asked her if my thyroid should be checked and thats the work up she did was the TSH and Free T4.

[goolarra]

Your TSH is a little low, but TSH is the least important of the thyroid tests.  TSH is a pituitary hormone and is susceptible to influence from any number of factors besides thyroid hormone levels.  Your FT4 is actually a tiny bit on the low side, but nothing at all to worry about.  Your doctor did not test FT3.  FT3 is the test that correlates best with symptoms.  In some thyroid conditions, FT3 is elevated even when FT4 is not.  

Heat intolerance is feeling hot when others around you are comfortable.  

I'd suggest you have FT3 tested (repeat TSH and FT4 and add in FT3).  In addition, you might want to be tested for thyroid antibodies to see if you have an autoimmune thyroid disease.  TSI (thyroid stimulating immunoglobulin) is the test for Graves' Disease (hyper), and TPOab (thyroid peroxidase antibodies) and TGab (thyroglobulin antibodies) are the two markers for Hashimoto's thyroiditis, which, though ultimately hypo, can be hyper in early stages.

Depending on the results of those, a thyroid ultrasound might be in order.