Diagnosis and tests

How to read my test results

Test results often reach your phone or inbox before you see your doctor: numbers, red flags, puzzling abbreviations. That can be unsettling. This topic calmly explains how to read, step by step, the reports you are most likely to see with leukemia — blood counts, bone marrow, flow cytometry and genetic results — what to pay attention to and which questions to ask your doctor.

Last updated: 30 September 2026~6 min read

Translucent glowing blood cells lined up along a gentle path of light running from left to right on a dark navy background, ending in a warm, calm light. — **Figure 1.**Concept: each result is a step on your path, not a single point.

01Short answer

Every laboratory report usually has the same parts: your details and the date the sample was taken, the name of the test, the result, the unit, the reference (normal) range and a flag for results outside it (for example, H for high and L for low). A reference range often covers the middle 95% of healthy people, so some healthy people will also have results slightly outside it. Ranges vary by laboratory, age and sex, and units can differ (×10⁹/L or thousand/µL, g/L or g/dL). In leukemia the trend — how results compare with earlier ones — matters more than any single number. In bone marrow, flow cytometry and genetic reports, the key part is the final “conclusion” or “interpretation” section, which sums up the blast percentage, immunophenotype and chromosome and mutation findings. During treatment, values such as MRD and, in CML, BCR::ABL1 are reported as percentages and compared with set targets. Never try to interpret a result on your own: write down your questions and discuss them with your hematologist.

02Simple explanation

First, take a deep breath. A result shown in red or flagged “H/L” is not automatically bad news. With leukemia and its treatment, some values are expected to be outside the normal range, and your doctor knows this.

On every line, look at four things: the name of the test, the result, the unit and the reference range. When you compare a result with one from another laboratory, make sure the units are the same.

Look at the trend, not a single number. For example, neutrophils slowly rising week by week after treatment tell you more than a slightly lower value on one particular day.

In complex reports (bone marrow, flow cytometry, genetics), read the final “conclusion” or “interpretation” first. The detailed tables are for specialists; what matters to you is the short meaning of the result.

Searching for individual numbers online often causes needless fear, because your own situation is not taken into account. A better way is to write down your questions and take them to your doctor.

03Scientific explanation

What is a reference range? According to MedlinePlus, a report shows whether your result falls within a reference range, also called “normal values”. Testing.com explains that for many tests this range is based on the middle 95% of a healthy reference group and most often differs by age and sex. This means that in roughly one in twenty completely healthy people, any single value can fall outside the range. MedlinePlus also points out that no test is perfect: false positive and false negative results are uncommon but possible.

Blood counts: in leukemia, white cells, neutrophils (ANC), hemoglobin, platelets and blasts matter most. US sources use “thousand/µL” and g/dL, while laboratories in Azerbaijan and Russia usually use ×10⁹/L and g/L: 1.0 thousand/µL = 1.0 ×10⁹/L, and 10 g/dL = 100 g/L. Blood chemistry values (liver, kidney, LDH) do not diagnose leukemia but matter for treatment safety (ACS).

A pathology report (including a bone marrow biopsy): according to the NCI and ACS, it usually contains a description of the sample, a microscopic description, the final diagnosis and comments. A marrow report records cellularity, the blast percentage and fibrosis; the flow cytometry section gives the immunophenotype (for example, “CD19+, CD10+, CD34+”), the cytogenetics section the karyotype (for example, “46,XY” or “t(9;22)”) and the molecular section the gene, the change and the variant allele frequency (VAF).

Percentages during treatment: in CML, BCR::ABL1 is reported as a percentage on the International Scale (IS); under ELN 2020, ≤0.1% at 12 months counts as a major molecular response. In AML, the 2021 ELN consensus uses a 0.1% threshold for flow-cytometry MRD. “Not detected” means below the test’s detection limit, not zero. Only your doctor can fully explain what these percentages mean for your treatment plan.

04What happens in the body?

Step 1: check the report “header”

Check that your name, date of birth and the date the sample was taken are correct. Note whether the sample is blood or bone marrow — the same value can mean different things in different samples. This small check helps prevent mistakes.

Step 2: a line, not a single number

Record your results by date in a simple table or notebook: white cells, neutrophils, hemoglobin, platelets. After a few weeks the trend will be easy to see. Doctors often base their decisions on exactly this trend too.

Small glowing cells arranged along a soft, gently rising wave of light on a dark navy background, with no axes, numbers or labels. — **Figure 2.**A trend tells you more than a single number.

Step 3: read complex reports together

Bone marrow, flow cytometry, cytogenetic and molecular results are pieces of one puzzle. They arrive at different times and only together give the full picture. Each time a new result comes in, ask: “What does this mean together with the earlier results?”

Four translucent glowing fragments — a cell, coloured dots, a chromosome and a DNA helix — drawing together on a dark navy background and joining in the centre into one complete glowing circle. — **Figure 3.**Blood, marrow, flow cytometry and genetic results are pieces of one picture.

Step 4: questions for your doctor

Useful questions: “Was this result expected?”, “Which three values matter most for me?”, “At what number should I call you straight away?”, “How do the genetic results change my risk group?”, “When is the next test?”. Write the answers down, or ask someone close to come with you.

Keep your results

Keep copies of all your reports in one folder — paper or digital. This helps a great deal when you see another doctor, get a second opinion or are treated at another clinic. According to the ACS, seeking a second opinion is normal, and doctors usually understand.

05Reading a report: four steps

From worry to clarity — a simple sequence.

1HeaderName, date, type of sample.

2Unit and rangeCompare the result with your laboratory’s range.

3TrendCompare with earlier results.

4DiscussionTalk your questions through with your hematologist.

A clear pictureA trend, not a single number.

A good conversationA well-prepared appointment.

SafetyKnowing when to call straight away.

06Common abbreviations on reports

Abbreviation	Meaning	Note
WBC / LEU	White blood cells	×10⁹/L (= thousand/µL)
NEUT, ANC	Neutrophils, absolute neutrophil count	The key measure of infection risk
HGB / Hb, HCT	Hemoglobin, hematocrit	g/L or g/dL (10 g/dL = 100 g/L)
PLT	Platelets	×10⁹/L
BLAST	Blasts (immature cells)	Not normally found in the blood
H / L	High / low	Outside the reference range
CD19+, CD34+	Marker present (flow cytometry)	“−” means the marker is absent
46,XY / t(9;22)	Karyotype notation	Normal male karyotype / a translocation
VAF	Variant allele frequency	Percentage of DNA carrying the mutation
IS %	BCR::ABL1 on the International Scale	Response to treatment in CML

* Abbreviations can differ between laboratories. Ask your doctor or nurse about any abbreviation you do not understand.

07Key terms

Reference range: The range of values a laboratory expects in healthy people.
H / L flag: Shows that a result is above (H) or below (L) the range.
Unit: The unit a result is expressed in, such as ×10⁹/L or g/L.
Trend: How results change over time.
False positive: A test showing a disease that is not there.
False negative: A test missing a disease that is there.
Pathology report: The written result of examining tissue or marrow under the microscope.
Not detected: A result below the test’s detection limit.
MRD: Measurable residual disease.
Second opinion: Another specialist’s view of the diagnosis or treatment plan.

08Key points

An “H/L” flag is not automatically bad news.
Look at the result, unit and reference range together.
Ranges vary by laboratory, age and sex.
The trend matters more than a single number.
In complex reports, read the final interpretation first.
“Not detected” does not mean zero.
Write down your questions and discuss them with your doctor.
Keep copies of all your reports.

09Frequently asked questions

My result arrived before I saw my doctor, and it is red. What should I do?

First, stay calm: many “red” results are expected with leukemia and its treatment. If you have symptoms such as fever, bleeding or severe weakness, call your care team straight away. If you have no symptoms, discuss the result at your next contact.

My result is just outside the range. Is that dangerous?

Usually not. Small deviations also occur in healthy people and can be due to dehydration, medicines or a recent illness. What matters is how your doctor weighs the whole picture.

Is it OK to look up my results online?

Reading general information from reliable sources can be helpful, but the internet does not know your specific situation. Use what you read as a source of questions and discuss them with your doctor.

Why do two laboratories give different results?

Because of different machines, methods, units and reference ranges. To follow the trend, use the same laboratory where possible; in CML, a laboratory that reports BCR::ABL1 on the IS standard is important.

Will my doctor be offended if I get a second opinion?

Usually not. A second opinion is common and normal practice with serious diagnoses. You can ask your doctor how to get copies of your reports and slides.

Who should I share my results with?

That is your choice. Many people bring someone close to appointments so they can hear and remember the information together. Keeping your reports in one folder is useful for showing them to other doctors.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

Which value in my results matters most?
What do the values marked with a star or in red mean for me?
Can we compare my results with earlier ones?
When should results be a reason for me to be concerned?

My questions

12Sources

MedlinePlus (U.S. National Library of Medicine). How to Understand Your Lab Results
MedlinePlus (U.S. National Library of Medicine). Complete Blood Count (CBC)
National Cancer Institute (NCI). NCI Dictionary of Cancer Terms: reference range
National Cancer Institute (NCI). NCI Dictionary of Cancer Terms: minimal residual disease
National Cancer Institute (NCI). Surgical Pathology Reports
National Cancer Institute (NCI). Questions to Ask Your Doctor about Your Diagnosis
American Cancer Society. Understanding Your Pathology Report
American Cancer Society. Blood Tests
American Cancer Society. Biomarker and Tumor Marker Tests
American Cancer Society. Second Opinions for Cancer Treatment
Testing.com. Reference Ranges and What They Mean
Testing.com. CBC With Differential Test: Order, Results & What They Mean
Leukemia, 2020. European LeukemiaNet 2020 recommendations for treating chronic myeloid leukemia
Blood (American Society of Hematology), 2021. 2021 Update on MRD in acute myeloid leukemia: a consensus document from the European LeukemiaNet MRD Working Party

Medical disclaimerThis information is for educational purposes only and does not replace medical advice.

Last updated: 30 September 2026← Back to the list

Open the interactive site →