Red cells, white cells and platelets. 14 markers, each with the guideline behind it, the ranges, what can affect it, what Passion Health does if it's out of range and when to retest.
Medically reviewed by Anantha Chentha, MD, Co-Founder and Chief Quality Medical Officer · October 30, 2026. Meet our cliniciansNext review: October 2027
Red cells, white cells and platelets.
Your infection-fighting cells.
Why it matters: Part of the complete blood count.
Ranges: Your lab's range applies.
What can affect it: Infections, steroids, smoking and some medicines.
If it’s out of range: Abnormal counts are rechecked or evaluated.
When to retest: As your clinician advises.
The most common white cell; fights bacteria.
Why it matters: Reported as an absolute count.
Ranges: Your lab's range applies; some healthy people run naturally low.
What can affect it: Infection, stress, steroids and ancestry.
If it’s out of range: Read with the full blood count.
When to retest: As advised.
White cells that fight viruses.
Why it matters: Reported as an absolute count.
Ranges: Your lab's range applies.
What can affect it: Viral infections and some medicines.
If it’s out of range: Read with the full blood count.
When to retest: As advised.
White cells that clean up damaged tissue.
Why it matters: Reported as an absolute count.
Ranges: Your lab's range applies.
What can affect it: Recovery from infection and chronic inflammation.
If it’s out of range: Read with the full blood count.
When to retest: As advised.
White cells involved in allergies and parasites.
Why it matters: Reported as an absolute count.
Ranges: Your lab's range applies.
What can affect it: Allergies, asthma and some infections.
If it’s out of range: Read with the full blood count.
When to retest: As advised.
Rare white cells involved in allergic reactions.
Why it matters: Reported as an absolute count.
Ranges: Your lab's range applies.
What can affect it: Allergic conditions.
If it’s out of range: Read with the full blood count.
When to retest: As advised.
The cells that carry oxygen.
Why it matters: Part of the complete blood count.
Ranges: Your lab's range applies.
What can affect it: Iron, B12, folate, bleeding and hydration.
If it’s out of range: Read with hemoglobin.
When to retest: As advised.
Condition guide: Anemia and iron deficiency guide
The oxygen-carrying protein in red cells.
Why it matters: Used to define anemia.
Ranges: Anemia is below 13 g/dL in men and below 12 g/dL in women (WHO).
What can affect it: Iron, B12 and folate levels, bleeding, pregnancy and altitude.
If it’s out of range: Anemia leads to iron, B12 or folate testing and a cause work-up.
When to retest: After treatment starts.
Condition guide: Anemia and iron deficiency guide
The share of your blood made of red cells.
Why it matters: Also monitored during testosterone therapy.
Ranges: Your lab's range applies.
What can affect it: Hydration, testosterone therapy and smoking.
If it’s out of range: High values on testosterone therapy change the dose.
When to retest: As advised.
Condition guide: Anemia and iron deficiency guide
Average red cell size.
Why it matters: Small cells suggest iron deficiency; large cells suggest B12 or folate deficiency.
Ranges: Your lab's range applies.
What can affect it: Iron, B12, folate, alcohol and thyroid.
If it’s out of range: Guides which nutrient to test next.
When to retest: As advised.
Condition guide: Anemia and iron deficiency guide
Average hemoglobin per red cell.
Why it matters: Calculated by the analyzer; read with MCV.
Ranges: Your lab's range applies.
What can affect it: Same as MCV.
If it’s out of range: Read with the full blood count.
When to retest: As advised.
Condition guide: Anemia and iron deficiency guide
Hemoglobin concentration in red cells.
Why it matters: Calculated by the analyzer.
Ranges: Your lab's range applies.
What can affect it: Iron status.
If it’s out of range: Read with the full blood count.
When to retest: As advised.
Condition guide: Anemia and iron deficiency guide
How much red cell sizes vary.
Why it matters: A high value can be an early sign of nutrient deficiency.
Ranges: Your lab's range applies.
What can affect it: Mixed nutrient deficiencies and recent treatment.
If it’s out of range: Read with MCV.
When to retest: As advised.
Condition guide: Anemia and iron deficiency guide
Cells that help blood clot.
Why it matters: Also used in the FIB-4 liver score.
Ranges: About 150–450 thousand per µL; your lab's range applies.
What can affect it: Infection, liver disease, iron deficiency and medicines.
If it’s out of range: Low platelets with high FIB-4 prompt a liver evaluation.
When to retest: As advised.
Education only. Your clinician interprets results with your history. Reference ranges vary by lab; your report shows ours.