Blood WorkAn RBC count is the number of red blood cells in a sample of your blood. It's part of a complete blood count (CBC); typical ranges are about 4.2 to 5.7 million cells per microliter for men and 3.8 to 5.1 million for women. A low count usually means anemia; a high count can come from dehydration, smoking, sleep apnea, lung disease, testosterone therapy or, rarely, a bone marrow condition.
What does an RBC count measure?
Red blood cells carry oxygen from your lungs to the rest of your body. The RBC count tells you how many there are. Clinicians read it with hematocrit and hemoglobin, which show how much of your blood is red cells and how much oxygen-carrying protein you have.
What is a normal red blood cell count?
| Group | Typical range |
|---|---|
| Men | About 4.2 to 5.7 million cells/µL |
| Women | About 3.8 to 5.1 million cells/µL |
Your lab's printed range applies, and pregnancy, altitude and age shift it.
What does a low RBC count mean?
A low count usually means anemia. Common causes:
- Low iron, B12 or folate. See the anemia and iron guide.
- Blood loss, from heavy periods or the gut.
- Kidney disease, which lowers the hormone that makes red cells.
- Long-term inflammation, pregnancy, or bone marrow problems.
Call 911 or go to the ER if a low result comes with chest pain, fainting or severe shortness of breath. Get care the same day for black or bloody stools.
What does a high RBC count mean?
- Dehydration, which concentrates the blood.
- Smoking, living at high altitude, sleep apnea or lung disease, where low oxygen drives more red cell production.
- Testosterone therapy. See the low testosterone guide for monitoring.
- Thalassemia trait, which can give a high count of small cells.
- Rarely, polycythemia vera, a bone marrow condition, or a tumor making extra red-cell hormone.
If your RBC count is off at Passion Health
A Texas-licensed clinician reviews every result and calls you the same day about anything critical. One result outside the range is common and often harmless; we read it with the rest of your panel, your history and your medicines, and recheck when that's the sensible next step.
For a low count we look at MCV, then ferritin, B12, folate and kidney function. For a high count we repeat it well hydrated and look at smoking, sleep, lungs and medicines; a persistently high count with no clear cause goes to a hematologist.
RBC test cost in Texas
Self-pay. The RBC count comes with every complete blood count. In Essential Blood Work ($59) it's part of 33 results with the draw and a clinician's review included; on its own, the complete blood count is $20 plus the $29 draw and review fee ($49).
With insurance. If we're in network with your plan, we bill it when the test is covered. You pay cash for a test only after we tell you the price in writing, and Medicare patients sign an Advance Beneficiary Notice first.
RBC blood test questions
What is RBC in a blood test?
RBC is your red blood cell count, the number of red cells in a sample of blood. It's part of a complete blood count. Typical ranges are about 4.2 to 5.7 million/µL for men and 3.8 to 5.1 million/µL for women.
What does a low RBC count mean?
Usually anemia: too few red cells to carry oxygen well. Iron, B12 or folate deficiency, blood loss and kidney disease are common causes.
What does a high RBC count mean?
Most often dehydration, smoking, sleep apnea or lung disease, or testosterone therapy. Rarely it's a bone marrow condition, which is why a persistently high count is looked into.
What is the difference between RBC and hemoglobin?
RBC counts the red cells; hemoglobin measures the oxygen-carrying protein inside them. They usually move together, but in thalassemia trait the count can be high while hemoglobin is normal or low.
Can dehydration raise my RBC count?
Yes. Less fluid in your blood makes the count look higher. Drink normally before your draw, and your clinician may recheck a high result when you're well hydrated.