Key Takeaways:
- If you get enough lab tests, everyone will have some labs that are “abnormal”
- Every body is different, so some of these “abnormal” results are your body’s normal
- Reference ranges are guidelines based on other people’s results and not tailored to you
- Context is usually more important (your other labs, health history, prior results, how you’re feeling)
- If in doubt or worried, you can and should ask about what your results mean for you
MCH
Normal range: 27.0 - 32.0 pg
The other day I logged in to my medical chart and saw a bright yellow “abnormal” label next to one of my blood tests. I clicked on it. There was no explanation. Just another alert telling me my value was “High.”
If I weren’t a doctor, I would be worried. The yellow demands attention. The green zone looks safe. It feels like a check engine light: something is either wrong or it’s not. But labs aren’t that simple. Thankfully, I’m a doctor—so I know my result is okay. Most people wouldn’t have that context. And why would you?
The Problem Isn't You
Most patient charts show you information similar to what physicians see. But a doctor can glance at an abnormal lab and know whether it matters. And even they ask colleagues for help with labs sometimes. You’re seeing the same data without years of training to interpret it.
And of course you don’t have that training. It would be impossible to have the same medical knowledge as a doctor and do everything else in your life. This is why the system should do a better job explaining what results might mean.
Ideally, you’d have enough time with your care team to talk through results before you see them. But right now, you see them first. You may, like many people, find yourself staring at alerts with no context, trying to figure out if you should worry.
One of the most confusing outcomes is when a lab is “abnormal,” yet your care team says you’re okay. Why does this happen?
Why Healthy People Get "Abnormal" Results
That “normal range” on your results isn’t a target you need to hit. For most labs, it’s a reference point to help understand your results.
Most reference ranges are created in such a way that sometimes healthy people will have “abnormal” values. To create the reference range a lab tests about 120 healthy adults. Because every body is a little different, the results vary. The lab takes the middle 95% of those results and calls that the “normal” range. The highest 2.5% and lowest 2.5% get labeled “abnormal.”
But, remember, all the people who were tested were healthy. This means that for many lab tests, 5 out of every 100 (5%) healthy people will have an “abnormal” result.
Some labs get their “normal” range by looking at studies or other methods. But all of these strategies have limitations. This means healthy people will have lab results outside of “normal” (the reference range).
How Reference Ranges (Normal) Are Set
120 Healthy People Are Tested
Get Enough Tests → You Might Have an "Abnormal" Result
What does this mean for you? If your labs measure 20 things in your blood, there’s a 38% chance that one will come back “abnormal.” This might sound like a lot of tests. But many tests can be performed on one tube of blood.
So the yellow flag could mean something. Or it could just be that your normal is different than most people.
How Reference Ranges (Normal) Are Set
120 Healthy People Are Tested
Reference Ranges Aren't Tailored to You
Remember, reference ranges are often based on about 120 people. That’s not many. If they’re younger, more muscular, or different from you, then what’s healthy for them may not be the same for you. This is also true if you have a health condition.
Imagine a blood test where the “normal” range is based on 20-year-olds. If you’re 65, your values will be different, because bodies change over time.
When a "Normal" Result Might Actually Be Concerning
This works the opposite way too. Reference ranges might not catch an important lab change.
Imagine your lab values always run at the high end of the normal range. That’s just how your body works. It’s your baseline. Then one day, your result comes back at the low end of normal. It’s still “normal” according to the reference range. But for you, that’s a big drop. And that drop could mean there’s a problem.
Normal Lab Results Can Be Abnormal for You
Results for a Lab Test
All flagged normal, but the last one is abnormal for this person
What You Can Do When You Get an Abnormal Result
Abnormal results make almost anyone feel nervous. You care about your health and want to understand what it means. This can be even more stressful when you don’t feel well. Below are some strategies that may help.
- If you feel worse or have concerning symptoms – Call your care team. They may not have seen the result yet. Your call will give them important information about how you’re feeling. And they can help you with next steps based on that and your lab result.
- Give it a little time – You probably saw your results before anyone has reviewed them. Your care team will get an alert, but they have many patients and need time to review everything. You should hear something within a few business days.
- If you haven’t heard back after a couple of days, reach out – It can be helpful to ask what the lab value means for you. This helps put the result in context with your health conditions, medications, and other results. And it’s important for you to get personalized information.
- If you’re still worried after getting an answer – Think about why. Are you not feeling well? Do you think the test missed something or might mean something specific? Let your care team know. This can help guide the conversation, since the lab is only one piece of the puzzle.
- Look at your previous results – Have you had this test before? Was it similar? If so, this might just be how your body works. If it’s very different from before, that’s worth mentioning.
- Make a note of what you learn – This way you’ll have context the next time you see this test.
These are rules of thumb, not hard rules. There are always exceptions. But hopefully they give you a starting point when you’re feeling anxious.
What You Can Do When Your Doctor Orders a Test
Before your next lab test, you can also ask:
- Why am I getting this test?
- What are you looking for?
- What result would be concerning?
This can help you know what to pay attention to when your results come back.
The Bottom Line
The colors and warnings on patient portals make it seem like something is either wrong or it’s not. But most labs don’t work that way. They need context. They need interpretation. They need someone who knows your health history to look at the bigger picture.
Not everyone has someone who can help you understand your labs. This is why we’re working on tools to help. Let us know if something else has helped you understand your lab values. Or if you have ideas about how we can better support you in understanding your results.
