Red cell indices (MCV, MCH, MCHC, RDW)
Quick answer: Red cell indices describe the size (MCV), haemoglobin content (MCH, MCHC) and size variation (RDW) of your red blood cells. They help doctors work out the type and likely cause of anaemia, such as iron deficiency, thalassaemia trait or low vitamin B12.
- SampleBlood
- TakesAbout 5 minutes
- Before the testNo special preparation is usually needed.
- In fertility careSmall red cells in pregnancy can point to iron deficiency or thalassaemia trait, and may lead to further tests for both partners.
How the test is done
- 1Blood is drawn into an EDTA tube
- 2An analyser measures red cell size and haemoglobin content
- 3The indices are worked out from these measurements
- 4Results are reported with your blood count
What your results can mean
Reading your report
These values are read together with haemoglobin and other tests; ranges differ between labs, so discuss them with your doctor.
If the result is outside the usual range
Small, pale cells (low MCV and MCH) can point to iron deficiency or thalassaemia trait, and large cells (high MCV) to lack of vitamin B12 or folate, alcohol or liver disease. A high RDW shows mixed cell sizes, often seen in iron deficiency.
Who usually has this test
People with anaemia, to help find its type, and anyone having a routine blood count.
Risks and aftercare
Bruising is possible, and no aftercare is needed.
Names and options
Also called: MCV, MCH, MCHC, RDW, RBC indices
Options
- MCH
- MCHC
- MCV
- MCV, MCH and MCHC together
- RDW
Listed by the hospital as
- MCH, EDTA BLOOD
- MCHC, EDTA BLOOD
- MCV, EDTA BLOOD
- MCV, MCH, MCHC (RED CELL INDICES)
- RDW, BLOOD
Questions about this test
How do the indices help tell iron deficiency from thalassaemia trait?
Both cause small cells, but thalassaemia trait often has a high red cell count and a normal RDW. Iron tests and haemoglobin electrophoresis confirm which it is.
What does a high MCV mean?
Large red cells can be seen with lack of B12 or folate, alcohol, or thyroid or liver problems. Your doctor may check B12 and folate.
Do I need a separate sample for red cell indices?
No, they come from the same sample as the blood count. They are printed as part of most CBC reports.
Related tests
Tamara Hospital & IVF Centre, Rajajinagar
34/3, 10th Cross Road, opp. Vardhaka Sardar Patel School, 1st N Block, 2nd Stage, Rajajinagar, Bengaluru 560010
The hospital is open 24 hours. Call before you come to check the timing for your scan or sample collection.
Get directions ↗IVF Pulse fertility care at Tamara Hospital →
Reception
Waiting area
IVF lab
This page explains each test in general terms so you know what to expect. It is not medical advice: your doctor decides which tests you need and what your results mean. Reference ranges differ between laboratories. Updated 4 November 2026.