Thyroid tests interpretation

Hello,

Thank you for your consult at DoctorSpring.com.

This report shows that TSH is low and the T4 is normal. TSH is a hormone that comes from the master gland pituitary , in the brain that controls the thyroid gland that produces T4. Whenever T4 levels increase, TSH levels go down as a response (feedback). In this case, this is just a milder form of that situation, where, although TSH is mildly reduced, T4 has not yet crossed the upper limit.

This situation can happen in two ways.
1. When the thyroid gland is inflamed (thyroiditis) and T4 is released into blood, causing its levels to rise and TSH levels to reduce. this is called thyrotoxicosis. The thyroid gland as such is functioning less than normal in this case. mostly, patients don't have any symptoms in this case.
2. When thyroid is functioning in excess, producing more T4, hence causing TSH to reduce. this is called hyperthyroidism. patients would present with increased pulse rate, tremors, weight loss etc.

TPO Antibodies are markers of autoimmune thyroiditis (when our own body makes antibody against our thyroid) and causes inflammation. it is increased in this case.

As I presume your daughter has no symptoms, this is most likely a case of autoimmune thyroiditis. It is a milder form of this condition, if at all, and there is no cause for concern.

This is a condition which doesn't require any medication but follow up with a repeat test after 3-6months to see how the gland progresses.

Based on the symptoms, test results, one may need to start her on medications in future (that is if the gland undergoes inflammation and loses its function). In that case, TSH will rise above normal, due to decreasing T4 levels. One will have to replace thyroxine hormone with tablet LevoThyroxine then.

I hope I have been able to allay your anxiety and answer your queries. Would be glad to answer any follow-ups.

Regards
Col (Dr) J Muthukrishnan, SM
Senior Adviser (Med & Endocrinology)

Thank you for your helpful information. What prompted this look into my daughter's thyroid is her trouble with depression. We have not been able to identify any situational cause for depression so we've been looking into her biochemistry (through her psychiatrist). Would these thyroid readings possibly be the start of Hashimoto's thyroiditis and have some relationship to depression? She also has increased fatigue lately, complains of cold hands and feet, and has seen 11 pounds of weight gain over the past 3 months (although this may be unrelated of course). I'm just trying to determine whether to keep considering the thyroid or just let it go, for a while at least. (We're also learning about a possible lack of folic acid in her system). Thanks again.
-Derek

I understand your anxiety. This is a case of Hashimoto's thyroiditis and thyroid function may deteriorate into mild and then overt hypothyroidism. Any degree of hypothyroidism (raised TSH) will require thyroxine replacement in her and would help her mood.
So you must repeat TSH after 3mths,then 6 mths, and then Annually.

Hope this helps, please feel free to discuss further.

I am continuing to struggle to figure out what is wrong with my daughter (age 15) and decided to revist her thyroid labwork. We seem to have several things going on at once and am not sure if or how they all relate. I asked you about her thyroid labwork before but failed to notice and report some other labwork results that may be important.

All of this began for us when we tried to address her problems with depression and the labwork showed low TSH, which prompted further thyroid tests. Her GP indicated that as long as the T4 is normal then there is nothing to do at the moment. In the meantime, her psychiatrist figured out that her body was not processing folic acided properly and put her on a megadose of methyl folate, and we pinned our hopes on this. So far however this has not produced any results, and her symptoms continue to worsen.
These symptoms include depression (often severe), weakness, constant light-headedness, shortness of breath, extreme low energy, constant exhaustion, constant muscle soreness especially in the calves, cold hands and feet, intolerance to heat, panic attacks and sudden feelings of doom. She is no longer able to participate in any physical activities (after working for years to successfully obtain a black belt in Tae Kwon Do). She still teaches Tae Kwon Do but only a few classes and does so with great struggle. It is doubtful she will be able to continue, especially when things get warmer.

What I believe to be the pertinent labwork numbers are as follows:

TSH: 0.059 uIU/mL
Anti-TPO-Ab: 84.9 IU/mL
Total T3: 130 ng/dL
T4: 10.5 ug/dL
Anti-Thyroglobulin: 134 IU/mL
Ferritin: 31 ng/mL (her other iron readings show normal)

We have tried medication to help her depression and nothing has helped. We took her to her GP to ask about her shortness of breath and she was tested for asthma (negative results). We have been trying various natural supplements. We are making sure she has proper nutrition and rest. Things just keep getting worse however and at this point we don't know where to turn.

I had understood before that we should test her thyroid again in some months and see where it is, especially in regard to her T4 level, but I think I overlooked your statement about thyroxine replacement. Is this something we should pursue right now, or only if a future test show a low T4 reading?

Thank you for your help.
Derek Chambers

Low TSh with a normal T4 doesnt require thyroxine at present, but you need to test her free T4 hormone levels.
Also, do check the early morning 8AM-9AM Serum Cortisol levels too. Adrenal insufficiency which may be seen with Hashimotos thyroiditis can cause these symptoms.
Her symptoms also may be related to thyroiditis, if the free T4 levels are high.