Second set of blood tests coming up.: I was... - Thyroid UK

Thyroid UK

137,156 members160,846 posts

Second set of blood tests coming up.

Jukebox1 profile image
2 Replies

I was diagnosed underactive thyroid in June, also suspected diabetes type 2 (nurse advised I could reverse with weight loss and exercise, and I have lost a stone) I am due for repeat blood tests now and wonder why people are being advised not to take their levothyroxine before the tests. Thank you.

Written by
Jukebox1 profile image
Jukebox1
To view profiles and participate in discussions please or .
Read more about...
2 Replies
shaws profile image
shawsAdministrator

Because if you have just digested levo a few hours beforehand, it skews the results completely and you may end up with the GP (as they only take notice of the blood test which they shouldn't do) reducing or keeping you on the same dose when in fact you may really need an increase.

Clutter profile image
Clutter

Jukebox, Levothyroxine peaks in the blood 2-6 hours after ingestion so taking it before your blood test means you are getting a measurement of the peak levels rather than the normal circulating levels. As Shaws said, this can mean that some doctors will reduce a patient's dose or fail to agree an increase which may be needed to resolve symptoms and effectively leaves a patient under medicated.

You may also like...

second set of blood tests

independent test..so in additional to my thyroid do i have any other concerns..? so I have had more...

Blood test coming up:

Hi, all - I'm having blood drawn next week to check my estrogen level and wondering if I should...

Confusing second set of tests

Please help me understand my most recent tests compared to me first ones. Old verses now results:...

Second set of test results any advice on what to do next please 😔

another load of blood tests. The Gp was only willing to test TSH and FT4 level and serum thyroid...

Second Opinion on Thyroid blood test?

Here are my thyroid blood tests TSH 3.833 (.3-5) FT4 1.1 (.7-1.5) I have been constipated, very...