Tips on preparing for home thyroid test please

[Rosalba]

Usually my thyroid tests are done at a private clinic which I can't now access due to Covid. I've ordered a home test via Blue Horizon - please could you remind me of the tips for preparing for your test. I seem to remember you're supposed to do it as early as possible in the morning and not to drink or eat beforehand. I normally take my levothyroxine at 0530 - do I take it as usual or wait until after I've done the test. Many thanks in advance.

[Cooper27]

You've to wait until after the test is done, to avoid influencing the test.

I always find it better to have a shower before doing the blood sample, and then holding my hand in a sink full of hot water for a few mins too. It just helps with blood flow.

[SeasideSusie Remembering]

Rosalba

Always advised here, when having thyroid tests:

* Blood draw no later than 9am. This is because TSH is highest early morning and lowers throughout the day. If looking for a diagnosis of hypothyroidism, an increase in dose of Levo or to avoid a reduction then we need the highest possible TSH

* Nothing to eat or drink except water before the blood draw. This is because eating can lower TSH and coffee can affect TSH.

* Last dose of Levo 24 hours before the test, take that day's dose after the blood draw (alter time the day before if necessary). Take after test on the day. This is because if you take your Levo before the blood draw the test will measure the dose just taken and show a false high. If you leave longer than 24 hours the result will show a false low.

* If you take Biotin or a B Complex containing Biotin (B7), leave this off for 7 days before any blood test. This is because if Biotin is used in the testing procedure it can give false results (most labs use biotin).

These are patient to patient tips which we don't discuss with phlebotomists or doctors.

TIPS FOR DOING FINGERPRICK TEST

* Be well hydrated, drink plenty of water the day before, and before you do the test.

* Some people take a shower before hand, some run up and down the stairs to get blood flowing. Personally, as I can't run up and down the stairs, I circle my arm round, windmill style.

* Have a bowl full of hot water, dip hand in and out, swish around, hand needs to go red. If blood flow stops, you can always swish round in the hot water again.

* Stand up to do the test. Make sure your arm is straight down when collecting the blood. Either use a small step stool to raise yourself well above the work surface, or put the collection tube on a lowish shelf. One member uses an ironing board so she can get the perfect height.

* Prick finger on the side, not the tip. I find that half way between the nail bed and tip is about right, or maybe slightly nearer the nail bed rather than the tip. I use my ring finger, but middle finger is next best for me.

* Do not squeeze your finger to get the blood out, it can damage the blood and it may not be usable

I've recently done 2 tests. The first one there was very little blood coming out which was unusual for me so I used a second finger and between the two I gradually filled the tube. However, when I checked the prick site for the first finger the actual cut was very small and as I've had some of these lancets fail before I put it down to that. When I did the second test this is what I did

* Prick my finger as usual, at the same time try and make a very slight twist with the lancet (the blade retracts very quickly so you have like a nano second to twist the lancet). I'm not talking 90 degrees or anything, just a very slight twist to make the cut just slightly bigger, it doesn't hurt or cause a blood bath! This made a big difference, 11 generous drops of blood filled the tube in less 2 minutes.

If you supplement with Biotin, or a B complex containing it (B7), leave it off for 7 days before doing any blood tests as it can give false results when biotin is used in the testing procedure, and most labs do use it.

Video showing how to do a fingerprick test:

youtube.com/watch?v=w2JzToZ...(Not working as expected?)

[Rosalba in reply to SeasideSusie]

thanks so much for this very comprehensive advice - super-useful.

[jimh111]

Postpone levo until after blood draw.

I disagree about food affecting TSH. I think the comment about coffee is a little confused. Coffee affects levothyroxine absorption but I've never heard of it affecting TSH (other than TSH would go up if coffee taken with levothyroxine).