How to prepare for a blood test: note what your doctor says

Your doctor ordered a test, and on your way out of the appointment you started wondering, "Was I supposed to come in fasting? Should I take my medicine?" Pre-test instructions are often given quickly, and by test day they may not have stuck. In this post we explain how to keep a simple prep note so you don't lose what your doctor told you.

Why should you write down pre-test instructions?

MedlinePlus explains that some test results can be affected by things like what you eat and drink, the medicines you take or the exercise you do, which is why following the instructions matters. Instructions vary from test to test; the way a relative prepared may not apply to your test.

The NHS also notes that your doctor or nurse will tell you whether you need to prepare. In other words, the right information isn't on the internet but with the person who ordered the test. Your job is to take what they say with you, accurately and completely.

A lot usually gets discussed at once during an appointment: a new medicine, the date of your next check-up, a referral and a test. Among all that, it's very easy to miss a short sentence like "Come in fasting in the morning." Remembering an instruction wrong can lead to frustrating outcomes such as having to repeat the test, which means both lost time and another needle.

Taking notes can also ease anxiety. Instead of wondering on the morning of the test, "Am I remembering this wrong?", you check your note and start the day more calmly.

6 questions to ask when a test is ordered

Before the appointment ends, or when you book the test, try to write down the answers to these questions:

1. Which tests are being ordered? Note their names, ideally exactly as written on the request form.
2. Do I need to fast? If so, ask for how long and whether you can drink water during that time.
3. How should I take my medicines and supplements? Mention everything you take, and ask your doctor what to do on the morning of the test.
4. Is there anything else I should avoid? For example, strenuous exercise, alcohol or smoking.
5. Where and when will the test be done? Do I need an appointment, and which times work?
6. When will the results be ready, and who will I talk to? Do I need a separate follow-up appointment for the results?

Feel free to use abbreviations when you write the answers, but make sure you'll still understand your own note on the morning of the test. If an answer feels unclear, ask right there: questions like "So I can't even drink water?" or "Which one is my morning medicine?" are never unnecessary. If your doctor or nurse gives you written instructions, taking a photo of that sheet and keeping it with your note is a good idea too.

MedlinePlus stresses that you shouldn't stop any medicine unless your doctor specifically tells you to. If you're not sure about an instruction, don't decide on your own; talk to your doctor or pharmacist. For general appointment prep, the post 7 notes to take to your doctor's appointment may also help.

How do you write a prep note?

Your prep note doesn't have to be long. A single entry for test day, just a few lines, is enough:

• Date and place: The day, time and address of the test.
• Ordering doctor: Their name and why they ordered the test, in one sentence.
• Instructions: Exactly as your doctor said them, without reinterpreting. For example, if they gave the fasting time in hours, write that number down as is.
• Medicine note: Whatever was said about your medicines, just as it was said.
• What to bring: The test request form, your ID and insurance details, and your glasses if you need them.

If you have tests done regularly, using the same headings each time makes things easier. At your next test you can look at last time's note and remember, "I went in fasting then too, and took my medicine afterwards." Still, keep in mind that instructions can change, so confirm them with your doctor every time. If you're going to a test with a loved one, for example an older parent, writing the prep note together means you both have the same information.

It's best to write the note as soon as you hear the instructions. Jotting down a few lines in the exam room or right after you leave, rather than writing what you remember once you get home, keeps details from slipping away. We covered the general way to organize your notes after an appointment in 5 steps to organize your notes after a doctor's appointment.

Test day and afterwards

The NHS explains that having blood taken usually only takes a short time, and that if you're nervous about needles you can tell the staff or bring someone with you. That's a small reminder you could add to your note as well.

• If you couldn't fully follow an instruction, for example if you ate something by mistake, tell the staff before the test. MedlinePlus also recommends being open about this.
• Note the time of the test and anything that caught your attention; these small details can come in handy at your next test.
• Write down when the results will be ready. According to the NHS, results can take anywhere from a few days to a few weeks; if the time you expected has passed, don't hesitate to ask.

Before you head out on the morning of the test, look at your note one last time: is the request form in your bag, did you follow the instructions, is the appointment time right? A short list of questions on your phone to ask while you wait at the lab also helps; for example, you can find out there where you'll be able to access your results.

Interpreting the results is your doctor's job. When you keep a result, it helps to also write the date, who ordered it and what you discussed with your doctor. To keep your results organized, see 6 ways to keep your lab test results organized. If you have an unexpected or worsening symptom after the test, contact your doctor; in a serious situation, call the emergency number in the country you're in.

Getting ready for test day with Oveluni

Oveluni is a personal record app where you can keep your medication plans, daily logs and check-ups in one place. Seeing your test day next to your other check-ups and noting your doctor's instructions in the same place makes it easier to find what you need that morning. Oveluni doesn't diagnose or interpret results; for questions about your tests and medicines, your doctor and pharmacist are always there for you. Oveluni is coming soon to the App Store.

Sources

1. MedlinePlus: How to Prepare for a Lab Test
2. NHS: Blood tests