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Thyroid UK
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Underactive thyroid blood test results?

ok I had a copy of my last blood test with results, but I have no clue what they mean except for some people have written about T in it? Serum free T4 level 15.7 pmol/L [11 - 24] Is this the right thing to look at? Thanks so much everyone :)

23 Replies


Can you post your other results and ranges too?


Result Abnormal, but expected What you need to do Make an appointment to see doctor

Urea and electrolytes

Serum sodium level 137 mmol/L [133.0 - 146.0]

Serum potassium level 4.8 mmol/L [3.5 - 5.3]

Serum creatinine level 77 umol/L [45.0 - 84.0]

Serum urea level 3.0 mmol/L [2.5 - 7.8]

eGFR using creatinine (CKD-EPI) per 1.73 square metres 80 mL/min [60.0 - 150.0]

New eGFR calculation from 02/10/17. Values should be multiplied by 1.159 for African-Caribbean patients. There may be minor changes in reported eGFR

Liver function tests

Serum alanine aminotransferase level 20 IU/L [10.0 - 36.0]

Serum alkaline phosphatase level 82 IU/L [30.0 - 130.0]

Serum total bilirubin level 4 umol/L [0.0 - 21.0]

Serum albumin level 47 g/L [35.0 - 50.0]

AST serum level 41 IU/L [0.0 - 31.0] Above high reference limit

Serum total protein level 73 g/L [60.0 - 80.0]

Haemoglobin A1c level - IFCC standardised

Haemoglobin A1c level - IFCC standardised 56 mmol/mol [20.0 - 44.0] Above high reference limit

Reference range quoted for non-diabetic individuals. Please see local guidelines for further interpretation in diabetes. When used for diagnosis: HbA1c >= 48 - repeat in 2 weeks if no symptoms HbA1c 42-47 - increased risk, repeat within a year but not within 3 months HbA1c < 42 - not diabetic, repeat not indicated

Serum cholesterol/HDL ratio Serum cholesterol level 3.7 mmol/L [< 5.0]

Serum HDL cholesterol level 0.58 mmol/L [1.0 - 3.0] Below low reference limit

Serum cholesterol/HDL ratio 6.4 [< 4.0] Above high reference limit

Serum non high density lipoprotein cholesterol level 3.1 mmol/L

Serum TSH level Serum TSH level 4.95 mIU/L [0.35 - 4.5] Above high reference limit

Serum free T4 level Serum free T4 level 15.7 pmol/L [11.0 - 24.0]


I have no idea what all that means? Is it bad?


Can you edit to make more readable by inserting line breaks and spaces


My doctor just told me that she would keep an eye on it!!!! I have made an appointment with another doctor, as I feel she was not understanding to my anxiety either. Got appointment on 8th March with different doctor, might be able to make it sooner, but that would be with another doctor I am not familiar with


Thank you to whoever edited my results for me. Thank you! :)

1 like


I've edited your results to make them more readable.

There are a some abnormal results which you should discuss with your GP:

TSH 4.95 is over range. Is that the first abnormal TSH result you've had?

Free T4 is within range but low-ish in range (normal).

Cholesterol above range may be due to underactive thyroid. Cholesterol usually drops once thyroid levels are good.

AST liver level is high and that may also be due to underactive thyroid and, like cholesterol, usually drops into normal range when thyroid levels are good.

Haemoglobin A1c is high and may indicate diabetes.

Everything else is within normal range.


Thank you for the editing. I appreciate it :) Have been Diabetic for 3 years now. I take Metformin for that. Yes, cholesterol has been high for many, many years, I take Simvastatin for that. I take Tramadol often for neck pain, and paracetemol, so that is why my liver result is high? I am very anxious!


Anxiety is a classic sign of being hypothyroid.



Had anxiety, and depression since I was 16.....45 now



Most of the results are as expected then.

I don't think you need to be anxious as AST isn't very high. Tramadol can elevate AST and, as I said before, so can hypothyroidism.



Do I need to book an appointment to see a doctor sooner, rather than later? Thanks so much for your help :)



I don't think either is urgent. Your practice would have called you if it was urgent. You're fine to wait for your March 8 appointment.

Was that the first high TSH thyroid test result you had?


Yes, as far as I am aware. They do blood tests a lot of the time, but never really say anything. The regular blood tests are for my Diabetes



TSH can be elevated due to an infection or virus so patients are often asked to repeat the test in 2-3 months when the non-thyroidal illness would be expected to have cleared.

If a second TSH test is abnormal your GP should prescribe Levothyroxine if you have symptoms of hypothyroidism. If not, it's okay to wait until TSH is >10.



Thank you so much for your help, and information. I appreciate it :)

1 like

Actually don't worry it's possible to read

Will add clear results in moment


Thank you so much! I am very anxious about this :(


TSH 4.95 (0.3-4.5)

FT4 15.7 (11-24)

Are these tests before you started on any Levothyroxine?

Or 6-8 weeks after being on a starter dose - usually 50mcg?


I have not been put on any medicines for it at the moment


Not surprised, you are only very slightly above range on TSH and FT4 is mid range.

Ask GP to test thyroid antibodies and vitamin D, folate, ferritin and B12 when bloods are retested

If they refuse you can test all these privately

For full Thyroid evaluation TSH, FT4, TT4, FT3 plus TPO and TG thyroid antibodies. Plus vitamin D, folate, ferritin and B12.

Essential to test thyroid antibodies plus vitamins

Private tests are available


Medichecks Thyroid plus ultra vitamin or Blue Horizon Thyroid plus eleven are the most popular choice. DIY finger prick test or option to pay extra for private blood draw. Both companies often have money off offers.

All thyroid tests should ideally be done as early as possible in morning and fasting. This gives highest TSH and most consistent results. (Patient to patient tip, GP will be unaware)

If antibodies are high this is Hashimoto's, (also known by medics here in UK more commonly as autoimmune thyroid disease). About 90% of all hypothyroidism in Uk is due to Hashimoto's


Make very sure the next test is very early morning ....fasting drinking only water

As then TSH will be at its highest so they are likely to treat you


Thank you for your reply. Sorry for the long delay. Have not logged in for some time. Currently dealing with other unexpected medical problems! I am not coping very well right now :(


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