Some information about our bodies can only be discovered through blood tests. Tests that are performed at home often need a finger prick to draw blood. People who have diabetes and don’t have a continuous blood glucose monitor may need to prick their fingers several times a day. This can become painful, which may cause you to avoid checking your blood sugar as often as you should.
What Is a Finger Prick?
A finger prick is a method of drawing drops of blood for at-home medical tests. These are most commonly used by people with diabetes to check their blood sugar (blood glucose) levels, but can also be used in other at-home test kits, such as tests for sexually transmitted diseases or hormone levels.
Finger pricks, also called finger sticks, are done using a device called a lancet. Lancets are needles or narrow, sharp blades that poke a small hole in the skin. There are two types of lancets used for collecting blood samples:
- Reusable devices: Reusable devices look similar to a pen. They allow you to replace a used lancet tip with a new one.
- Single-use, auto-disabling fingerstick devices: Single-use devices are meant to be used once and then thrown away. They have an auto-disabling feature that prevents the lancet from being used again and makes them safe to dispose of.
Never share your finger prick lancets with anyone, as this can spread bloodborne diseases.
How to Do a Finger Prick Test
Finger prick tests don’t have a lot of difficult instructions, but they can be hard if you have a weak stomach or aren’t used to doing a finger prick on yourself.
To do a finger prick test:
- Start by washing your hands thoroughly with soap and warm water. Skipping this step could contaminate the test and alter your numbers.
- Unpack your testing supplies on a clean surface.
- If you’re drawing blood for a test you’ve never done before, like an at-home lab kit, read through all of the instructions so you don’t miss anything important.
- Set up whatever equipment you need before you run the test. For a blood glucose test this may involve inserting a test strip into your monitor, while a lab test may need you to have the collection tube handy.
- Use an alcohol wipe or sanitizer on the finger you plan to prick.
- Press the lancet into your fingertip to draw blood. Different lancets work in different ways, so always read the instructions before you do this.
- Some test kits may ask that you wipe away the first drop of blood with a tissue to help avoid contamination.
- Collect the blood sample. This will work differently depending on what you’re collecting the blood for.
- When testing your blood sugar, touch the tip of your test strip into the blood.
- When providing a blood sample for a lab test, you may need to collect the blood in a vial. This often takes more blood than the glucose test.
- If you’re doing an at-home lab test and are struggling to collect enough blood, try massaging the tip of your finger to encourage blood flow. Some test kits may include a spare lancet so you can try drawing blood from a second finger.
- Apply a bandage if needed.
Tips to Reduce Finger Prick Pain
For people with diabetes, who may have to prick their fingers several times a day, finger pricks can quickly become painful.
There are a few things you can do to reduce finger pain from finger sticks:
- Prick the sides of your fingers, not the very tip. Pricking the very tip of your finger is more painful, and you may not be able to draw enough blood. The sides of your fingers have fewer nerves and more blood vessels closer to the surface.
- Alternate which fingers you prick. This prevents one specific finger from becoming sore. Try creating a pattern, like using different fingers for different days of the week.
- Some people prefer to use the same site over and over and develop a callus. This means a deeper lancet prick but may reduce pain.
- Instead of using an alcohol wipe or sanitizer, wash the finger you’re going to prick thoroughly with soap and water. Alcohol-based sanitizers dry out and tighten the skin, making pricks more painful.
- If your blood glucose monitor allows it, try taking blood from an alternate site like the arms or legs. Never take blood from the feet or toes, as this can cause infection, especially in people with diabetic neuropathy.
- Try a cream or lotion specially formulated for people with diabetes.
If you’re struggling, it could be that you aren’t using the best equipment for you:
- Do not reuse lancets. This dulls them, making finger pricks more painful and increasing the risk of infection.
- Try adjusting your lancet. Some lancet devices are adjustable, so you can choose how deeply they prick. Use the shallowest setting possible, as deeper pricks will hurt more.
- Choose a different blood glucose meter. Some meters can use less blood for testing, and some can be used on other areas of the body.
If you’ve pricked your finger but are struggling to get enough blood for a test, drop your hand below your waist and count to five. This helps increase blood flow to the area. If you’re still struggling, gently squeeze your finger, starting at the base and working your way up to your fingertip. Don’t squeeze right at the prick site, as this will cause more pain.
If you know you typically have a hard time getting enough blood, try these tips before lancing your finger:
- Rub the spot on your finger that you are going to lance until it gets warm.
- Shake your hand down at your side to increase blood flow.
- Create a tourniquet on your finger by wrapping something like a rubber band around the middle joint. This causes the tip of the finger to swell with blood. Remove the tourniquet immediately after pricking.
How to Check Blood Glucose
Checking your blood glucose involves a few more steps than just a finger prick:
- Gather everything you need, including your blood glucose monitor, test strips, and lancet.
- Thoroughly wash your hands, taking special care with the finger you’re going to prick. Dry your hands completely.
- Insert the test strip into the monitor.
- The finger prick for glucose testing follows the same steps outlined above. Prick your finger with the lancet. Lancet instructions may vary by type.
- Touch your test strip to the blood.
- After a few seconds, your monitor will display your blood glucose numbers. Low blood sugar is typically considered anything below 70 mg/dL, and high blood sugar is usually anything above 125 mg/dL, but your doctor will let you know what range you should be in.
- Safely discard your lancet, record your numbers, and put your supplies away.