Is RBC 3.99 low, normal or dangerous? What does Red blood cell count level 3.99 mean?

📅 Medical Review Date: November 25, 2025

Your RBC level of 3.99 is a Low RBC level.

If you are a male and your RBC is in between 4.5 mil/uL and 5.5 mil/uL, or if you are a female and your RBC is in between 5 mil/uL and 6 mil/uL then you need not worry as 4.5-5.5 mil/uL is the normal range for men and 5-6 mil/uL is the normal range for women. But if your RBC is lesser or greater than the above values, then there may be some problem in your body.

Important - Scroll to the end of this article to see how our patients managed their low RBC levels

The normal RBC range for men is :4.5 - 5.5 mil/uL

**Ideal values of RBC depending on age (male) :**
Age	Ideal RBC value
<5 years	4.68
5-10 years	4.867
10-15 years	5.061
15-20 years	5.263
20-25 years	5.473
25-30 years	5.464
30-35 years	5.455
35-40 years	5.447
40-45 years	5.438
45-50 years	5.429
50-55 years	5.421
55-60 years	5.412
60-70 years	5.403
70-80 years	5.395
80-90 years	5.386
90-100 years	5.378
>100 years	5.37

*Ideal values are calculated based on our database of patient records

Get Advice via Email : Send us your blood test report, and our RBC experts will review it. You'll receive a detailed analysis and personalized treatment guidance via email within 12 hours. If you have additional blood test results besides RBC, please include those too—an accurate diagnosis often requires a full view of all abnormalities. Upload blood test report now

1,51,150

Total number of patients treated

Important - Read more questions about low RBC levels after this video message

A video message on the treatment of your low RBC level

If you want your blood test report to be interpreted by RBC specialist, you can upload your report. Our RBC expert will provide you with the most accurate interpretation of your blood test results and treatment within 12 hours.Upload blood test report now

Important - At the end of this article read how our patients treated their low RBC levels

Some examples of conditions that increase or decrease RBC levels include:

Sudden (acute) or chronic bleeding from the digestive tract
Kidney failuresevere and chronic kidney diseases lead to decreased production of erythropoietin
Bone marrow damage
Conditions that cause red blood cells to be destroyed, such as hemolytic anemia caused by autoimmunity or defects in the red cell itself
Chronic bleeding from the digestive tract

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Important - At the end of this article read how our patients treated their low RBC levels

Also Read :How our patients treated their low rbc?

Normal range of RBC found among women :5-6 mil/uL

**Ideal values of RBC depending on age (female) :**
Age	Ideal RBC value
<5 years	5.205
5-10 years	5.419
10-15 years	5.642
15-20 years	5.874
20-25 years	5.864
25-30 years	5.854
30-35 years	5.845
35-40 years	5.835
40-45 years	5.825
45-50 years	5.815
50-55 years	5.805
55-60 years	5.796
60-70 years	5.786
70-80 years	5.776
80-90 years	5.766
90-100 years	5.756
>100 years	5.993

Upload your blood test report

If you take a RBC blood test and the results are not in the normal range (4.5-5.5 mil/uL), your physician may recommend more tests to figure out the problem. You might also get this test if your physician thinks you have some other disease.

Important :How our patients treated their low rbc?

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How the RBC Test Is Done :

When your doctor orders a RBC test, it involves a straightforward blood draw to measure your RBC levels. A pathologist or lab technician will take a small sample of blood from a vein using a needle. Your RBC test results are usually available within a few hours.