I'm having trouble with blood sample, what can I do?

Taking a blood sample can be tricky, especially the first time you do it. If you’re struggling to fill the sample tube with enough blood, but you’ve managed to fill it to the 400 line, you can send this to the lab. They will try to use this for the tests. If there’s not enough blood for them to test, we’ll let you know and send you a new test kit. If you cannot fill the sample tube to the 400 line, we can send you a new test kit so you can try again. Contact us and include your mobile number, date of birth and postcode, so that we can find your record and organise this. Here’s some things you can try to make it easier to take a sample and improve the blood flow: Get very hydrated before you start - drink more water than usual the day before you take the test Take your sample with the tube sitting below you and keep your arm straight. This way gravity can play a part and make it easier. Putting the tube on a low flat surface - like a toilet seat or low bench - and positioning yourself over it can help. Being warm really helps too. You could try holding a warm drink for a few minutes, running your hand under warm water or doing the test after you’ve had a bath or shower. We’ve heard from some people that using their thumb or the side of a fingertip can often produce more blood. You will need to 'milk' your finger to help the blood to flow out, if you start at the knuckle and gently squeeze down towards the tip of your finger this can help the blood to come out more easily. If you’d prefer to have a clinician take the blood sample for you, you can do this at a sexual health clinic. If your test kit contains swab or urine tests as well as blood, you can send back these samples without the blood sample and we can test those for chlamydia and gonorrhoea.

Frequently asked questions

Using our tests

Taking a test

Taking a blood sample can be tricky, especially the first time you do it.

If you’re struggling to fill the sample tube with enough blood, but you’ve managed to fill it to the 400 line, you can send this to the lab. They will try to use this for the tests. If there’s not enough blood for them to test, we’ll let you know and send you a new test kit.

If you cannot fill the sample tube to the 400 line, we can send you a new test kit so you can try again. Contact us and include your mobile number, date of birth and postcode, so that we can find your record and organise this.

Here’s some things you can try to make it easier to take a sample and improve the blood flow:

Get very hydrated before you start - drink more water than usual the day before you take the test
Take your sample with the tube sitting below you and keep your arm straight. This way gravity can play a part and make it easier. Putting the tube on a low flat surface - like a toilet seat or low bench - and positioning yourself over it can help.
Being warm really helps too. You could try holding a warm drink for a few minutes, running your hand under warm water or doing the test after you’ve had a bath or shower.
We’ve heard from some people that using their thumb or the side of a fingertip can often produce more blood. You will need to 'milk' your finger to help the blood to flow out, if you start at the knuckle and gently squeeze down towards the tip of your finger this can help the blood to come out more easily.

If you’d prefer to have a clinician take the blood sample for you, you can do this at a sexual health clinic.

If your test kit contains swab or urine tests as well as blood, you can send back these samples without the blood sample and we can test those for chlamydia and gonorrhoea.

Find a clinic near you

Yes, you can. But your test will be more accurate if you do it on a lighter day of your period or if you wait until you've stopped bleeding.

Use the return packaging included in your kit to securely send your samples to our lab. This has our address label already attached and the postage has been paid.

This is UN3373 packaging. It’s approved for transporting medical samples and will keep your samples safe.

You might like to make a note of the # number on the address label. This can be used to track your samples with Royal Mail.

Then you can just put the sealed package in any local postbox. There is no need to visit the post office.

If you did not get any return packaging in your kit, let us know by replying to one of our text messages, or emailing us at sh24.info@nhs.net. Include the mobile number you used to make your order, your date of birth and your postcode, so we can find your order and organise new packaging to be sent to you.

Our lab cannot accept samples received in any other packaging. Or samples that we have not sent you. This is because different packaging may allow your samples to become contaminated on their journey.

Our test kits

Some parts of the test kit will expire, but usually you can keep the kit for a few months and use it when you’re ready.

You can find expiry dates written on the sides of the individual pieces of your test kit, for example, on the side of the sample tube.

If you’ve had your kit for over 6 months, we recommend ordering a new one in case our testing or posting has changed.

Here’s how you can prepare for the conversation

Our simple home STI test kits are highly accurate and reliable when you:

follow the instructions carefully
wait for the recommended window period before you test
do more tests in a clinic after a reactive result for HIV

Your samples are sent to our partner laboratory to be processed by specialist technicians. We use the same tests that many NHS clinics use.

The window period is the time it takes for an infection to show up in tests. This period starts from the time of your sexual health risk - when you think you may have been exposed to infection.

Find out the best time to test

At our labs, we use the nucleic acid amplification tests (NAATs), run on the Hologic Panther platform to test for chlamydia and gonorrhoea.
Our HIV test is a fourth-generation assay test. This tests for HIV I and II antibodies and p24 antigen (a protein often present in the blood soon after infection). This is the most up-to-date test as recommended by BHIVA (British HIV Association)

Our syphilis test is an ECLIA (ElectroChemiLuminescence ImmunoAssay). This test looks for antibodies known as immunoglobulins IgG and IgM. Our lab screens for both HIV and syphilis using the Roche Cobas E Modular platform.