Red blood cell indices





Definition

Red blood cell (RBC) indices are calculations derived from the complete blood count that aid in the diagnosis and classification of anemia.

Purpose

Red blood cell indices help classify types of anemia, a decrease in the oxygen carrying capacity of the blood. Healthy people have an adequate number of correctly sized red blood cells containing enough hemoglobin to carry sufficient oxygen to all the body's tissues. Anemia is diagnosed when either the hemoglobin or hematocrit of a blood sample is too low.


Description

Measurements needed to calculate RBC indices are the red blood cell count, hemoglobin, and hematocrit. The hematocrit is the percentage of blood by volume that is occupied by the red cells. The three main RBC indices are:

  • Mean corpuscular volume (MCV). The average size of the red blood cells expressed in femtoliters (fl). MCV is calculated by dividing the hematocrit (as percent) by the RBC count in millions per microliter of blood, then multiplying by 10.
  • Mean corpuscular hemoglobin (MCH). The average amount of hemoglobin inside an RBC expressed in picograms (pg). The MCH is calculated by dividing the hemoglobin concentration in grams per deciliter by the RBC count in millions per microliter, then multiplying by 10.
  • Mean corpuscular hemoglobin concentration (MCHC). The average concentration of hemoglobin in the RBCs expressed as a percent. It is calculated by dividing the hemoglobin in grams per deciliter by the hematocrit, then multiplying by 100.

The mechanisms by which anemia occurs will alter the RBC indices in a predictable manner. Therefore, the RBC indices permit the physician to narrow down the possible causes of an anemia. The MCV is an index of the size of the RBCs. When the MCV is below normal, the RBCs will be smaller than normal and are described as microcytic. When the MCV is elevated, the RBCs will be larger than normal and are termed macrocytic. RBCs of normal size are termed normocytic.

Failure to produce hemoglobin results in smaller than normal cells. This occurs in many diseases, including iron deficiency anemia, thalassemia (an inherited disease in which globin chain production is deficient), and anemias associated with chronic infection or disease. Macrocytic cells occur when division of RBC precursor cells in the bone marrow is impaired. The most common causes of macrocytic anemia are vitamin B 12 deficiency, folate deficiency, and liver disease. Normocytic anemia may be caused by decreased production (e.g., malignancy and other causes of bone marrow failure), increased destruction (hemolytic anemia), or blood loss. The RBC count is low, but the size and amount of hemoglobin in the cells are normal.

A low MCH indicates that cells have too little hemoglobin. This is caused by deficient hemoglobin production. Such cells will be pale when examined under the microscope and are termed hypochromic. Iron deficiency is the most common cause of a hypochromic anemia. The MCH is usually elevated in macrocytic anemias associated with vitamin B 12 and folate deficiency.

The MCHC is the ratio of hemoglobin mass in the RBC to cell volume. Cells with too little hemoglobin are lighter in color and have a low MCHC. The MCHC is low in microcytic, hypochromic anemias such as iron deficiency, but is usually normal in macrocytic anemias. The MCHC is elevated in hereditary spherocytosis, a condition with decreased RBC survival caused by a structural protein defect in the RBC membrane.

Cell indices are usually calculated from tests performed on an automated electronic cell counter. However, these counters measure the MCV, which is directly proportional to the voltage pulse produced as each cell passes through the counting aperture. Electronic cell counters calculate the MCH, MCHC, hematocrit, and an additional parameter called the red cell distribution width (RDW).

The RDW is a measure of the variance in red blood cell size. It is calculated by dividing the standard deviation (a measure of variation) of RBC volume by the MCV and multiplying by 100. A large RDW indicates abnormal variation in cell size, termed anisocytosis. The RDW aids in differentiating anemias that have similar indices. For example, thalassemia minor and iron deficiency anemia are both microcytic and hypochromic anemias, and overlap in MCV and MCH. However, iron deficiency anemia has an abnormally wide RDW, but thalassemia minor does not.


Diagnosis/Preparation

RBC indices require 3–5 mL of blood collected by vein puncture with a needle. A nurse or phlebotomist usually collects the sample.


Aftercare

Discomfort or bruising may occur at the puncture site. Pressure to the puncture site until the bleeding stops reduces bruising; warm packs relieve discomfort. Some people feel dizzy or faint after blood has been drawn and should be allowed to lie down and relax until they are stable.


Risks

Other than potential bruising at the puncture site, and/or dizziness, there are no complications associated with this test. However, certain prescription medications may affect the test results. These drugs include zidovudine (Retrovir), phenytoin (Dilantin), and azathioprine (Imuran). When the hematocrit is determined by centrifugation, the MCV and MCHC may differ from those derived by an electronic cell counter, especially in anemia. Plasma trapped between the RBCs tends to cause an increase in the hematocrit, giving rise to a somewhat higher MCV and lower MCHC.

Normal results

Normal results for red blood cell indices are as follows:

  • MCV: 80–96 fl
  • MCH: 27–33 pg
  • MCHC: 33–36%
  • RDW: 12–15%

Resources

BOOKS

Chernecky, Cynthia C., and Barbara J. Berger. Laboratory Tests and Diagnostic Procedures. 3rd edition. Philadelphia: W. B. Saunders Company, 2001.

Henry, J.B. Clinical Diagnosis and Management by Laboratory Methods. 20th ed. Philadelphia: W. B. Saunders Company, 2001.

Kee, Joyce LeFever. Handbook of Laboratory and Diagnostic Tests. 4th edition. Upper Saddle River, NJ: Prentice Hall, 2001.

Wallach, Jacques. Interpretation of Diagnostic Tests. 7th edition. Philadelphia: Lippincott Williams & Wilkens, 2000.

OTHER

National Institutes of Health. [cited April 5, 2003]. http://www.nlm.nih.gov/medlineplus/encyclopedia.html .


Victoria E. DeMoranville Robert Harr Mark A. Best

User Contributions:

anonomous
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Mar 28, 2009 @ 11:23 pm
Hello,
is it possible for someone to have a small size RBC and not be anemic?..what can be other causes of low size RBC?...
Dr.Ateeq
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Apr 14, 2009 @ 4:16 pm
It is necessary for a patient to be anemic, having microcytosis..
anonymous 2
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Apr 24, 2009 @ 5:17 pm
I have abnormally small RBCs but I am not anemic or even close to anemic. The doc doesn't know why this is, but I was there for multiple symptoms including major fatigue, aching under arms, inability to process fats (as tested), but a few CTs later and a couple of invasive tests--they don't see any tumors (looking for cancer) and Celiac was negative....but I definitely don't feel well. Are there other reasons for a small RBC? --I've never had anyone tell me this before....
Jennifer
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Apr 28, 2009 @ 10:10 am
I have a high MCH and a low MPV in my blood test. I saw that a MCH that is elevated is usually elevated in macrocytic anemias. what does that mean?
frances
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May 29, 2009 @ 11:11 am
great article!you should read this article.especially if you tend to have anemia
Cathy Kent
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Jun 23, 2009 @ 8:20 pm
I'm not sure what all of the above means, all I know is I wa told I'm anemic my hemoglobin is was 9.0 but it is up to 10.6 now it dropped fro, 11.4 I've had other scanns done and they were negative but I do not feel well sometims. I get lighted a lot. My doctor wants me to go to a doctor tha specializes in blood. She mention there is something in my blood that should be elevated above wove 2000 to 8000 but mine is right at 2000. I won't see her until after I see the specialist can you please explain to me what this is all about.
Myriam Lemal
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Oct 16, 2009 @ 12:12 pm
My MCHC is 30.5. I read that it is low. What do I have to do? Any recommendations? Thank you.
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Feb 7, 2010 @ 4:04 am
My RDW count is at 19.3 percent,my iron is normal,WBC is at 14 percent,what would this normally indicate?
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Mar 24, 2010 @ 4:16 pm
I came back form my GP today with the following results
HB 8.4, RBC 4.22, Haematocrit 0.322, MCV 76.2, MCH 20.3, MCHC 26.7, RDW 16.3, Platelet count 145

Any advice would be really appreciated - thank you
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May 28, 2010 @ 10:10 am
hi 2 week ago i had a blood test and they came back i had high mpv so my doctor sent me for another blood test checking my liver, amino acids and vitamin b these have all come back ok, therefore does anyone have any other idea what may be causing this as i cant speak to my gp until tuesday, thanks
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Jun 22, 2010 @ 5:05 am
6.357 - RBC count high 4.380 - 5.770
320.3 - mchc blood count low 326.5 - 356.0
76.7 - mcv blood test is low 80.7 - 95.5
24.56 - mch blood test low 27.20 - 33.50

Is it fine or something wrong...

Thanks
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Jun 22, 2010 @ 5:05 am
6.357 - RBC count high 4.380 - 5.770
320.3 - mchc blood count low 326.5 - 356.0
76.7 - mcv blood test is low 80.7 - 95.5
24.56 - mch blood test low 27.20 - 33.50

Is it fine or something wrong...

Thanks
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Aug 22, 2010 @ 10:10 am
which of these can affect the MCV: infusion of glucose,transfusion of blood,transfusion of platelets ?
DARPAN
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Sep 25, 2010 @ 3:15 pm
total RBC - 5.91
mchc -30.8
mcv - 77
mch - 23.7
pcv - 45.6
haemoblobin - 14
Platelet - 169000

Please let me know if anything is wrong.
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Jan 7, 2011 @ 12:12 pm
My son has small red blood cells but is not anemic , he has had a fever , loss of appetite ,fatigue,loss of weight and his white cell count is a little higher than normal any ideas???
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Jan 12, 2011 @ 9:09 am
WHAT IS EFFECT OF MCV IF IT IS MORE IN RBC INDICES, IF MCV IS 97FEMTOLITER IN BLOOD.SO PLZ LET ME KNOW SIDE EFFECT ON BODY
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Feb 3, 2011 @ 9:21 pm
Hi i just got my results, i am from Australia, Lebanese background, and was told i have thalassemia which is from Mediterranian, Africans and Asians or hereditary . My iron level was tested too, it was 25, the doctor said thats "good", but i am afraid he could be wrong as i read somewhere else..it should be higher...the test said "either thalassemia/and or Iron deficiency" how do i know which one, as i am not sure if the doc is right..thanks
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Feb 12, 2011 @ 11:11 am
HELLO,
MY DAD IS INTENSIVE CARE BECAUSE HE HAS BEEN SICK. THEY SAY HIS RED CELLS ARE 7.9 (SEVERE). THEY PUT RED BLOOD INTO HIM AND IT DISAPPEARED. THEY CAN NOT FIGURE OUT WHERE IT WENT. HE HAS BEEN NOT EATING, PALE, AND SLEEPS ALOT BEFORE GOING INTO HOSPITAL. HE NOW HAS A BREATHING TUBE BECAUSE HIS HEART WAS RACING SO BAD. THEY WANT TO DO A COLONOSCOPY AND ENDOSCOPIC BUT HAVE TO WAIT TILL HE CAN UNDER ANESTHIA. THEY HAVE HIM HEAVILY SEDATED BECAUSE OF BREATHING TUBE. DO YOU KNOW WHERE THE BLOOD WOULD GO. IF IT WAS LIKE LEUKIMIA IT WOULD HAVE SHOW UP ON BLOOD TEST. WOULD IT? PLEASE HELP ME IF YOU COULD.
THANKS VERY MUCH
VIRGINIA LAAG
anonymous
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Feb 15, 2011 @ 10:22 pm
my daughter have low hemoglobin and high hematocrit, with high rbc and low wbc , what is the indicaton?
Anonymous
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Apr 18, 2011 @ 12:12 pm
Please tell me if the numbers below provide any suggestions regarding the cause of anemia. My LDH is consistently normal, B12 very good, Folate very good, Vitamin D Deficiency, Sed Rate = 85 Multiple Iron Infusions (>20), No GI Bleeding,Lupron 1/2011 and 4/2011, No M Spike, Very good liver and kidney function, High SSDNA, but normal DSDNA

12/29/101/7/11 1/14/11 1/20/11 1/21/11 2/10/11 2/17/11 3/18/11 4/8/11
RBC 3.07 3.3 3.02 3.19 2.81 3.54 3.85 3.84 4.02
HGB 9.6 10.1 9.4 10.5 8.6 11.6 11.7 11.8 12.3
HCT 30.5 32.3 29.5 30.6 27.3 35 37 36.1 37.2
MCV 99.4 98 97.6 96 97.1 99 96.2 94.1 92.5
MCH 31.3 30.6 31.1 32.9 30.6 32.7 30.4 30.7 30.6
MCHC 31.5 31.3 31.9 34.4 31.5 33.1 31.6 32.7 33.1
RDW 14.9 14.1 14.7 13.1 13.9 15.2 14.5 14.8 14.7
PLT 433 430 413 519 427 335 369 389 349
_MPV 8.3 8.5 8.8 8.6 15.2 9.2 8.7 9
FERRTN 59 84.7 75 38 27
Missy
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Apr 25, 2011 @ 11:11 am
I am folate deficient no matter how many supplements I take and my RBC count is low and my MCH level is high so it could possibly be pernicious anemia which is a common chronic condition oftentimes alleviated with monthly b-12 injections at any internal medicine physician's office.
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Apr 27, 2011 @ 9:09 am
Dear Sir, I recently experienced some minor fainting spells which took to an overnight stay in the hospital. Everything checked out fine and it was put down to a virus. However I was called back to take a further blood testwityh the comment [ One of the measurements of red blood cells [MCHC] were slightly on the high side, the rest of the tests were fine.]
Can you give me an indication of what they are looking for ?.
Best regards John H
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Jun 2, 2011 @ 11:11 am
hi im ASIAN(Filipino)female, 24 years olad.After consulting to an ortho dr here in riyadh saudi arabia,he diagnosed me with ARTHRITIS..i UNdergone xrays and laboratory like ESR,ASOT,Rheumatoid Factor,Uric acid all was normal but in my CBC shows somewhat bit increasingly deviated to normal.those result was:

total RBC - 4.44 10e6/uL
mchc -35.5 g/dl
mcv - 98.7 fl
mch -35 pg
RDW- 10.8%
haemoblobin - 15.5 g/dl
Platelet - 197 10e3/uL
MPV-6.28 fl
please notify me if there's any thoughts you have regarding my case.ty so much.
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Aug 24, 2011 @ 12:00 am
what is the difference between MCH and MCHC?isn't MCHC supposed to rise when Mch increases?please clearly explain.
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Aug 24, 2011 @ 3:15 pm
should i be concern about these blood test hemoglabin10.1,hematocrit30.8,mcv76.9,mch25.1,rdw15.9
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Sep 24, 2011 @ 12:12 pm
Reasons for low MCH 25.5Pg and MCHC 31.52% Eosinophils 10%
indicate the treatment to improve it.

Thank you,
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Sep 24, 2011 @ 10:22 pm
its interesting for research purpose particularly for the young research workers interested in the medical field. the RDW is still denied in the general medical practice untill its established and made as specific criterion in the diagnosis or prognosis of disease
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Sep 28, 2011 @ 1:13 pm
i would like to know having a high rdw what can acure its slowing going up from 15.7 then 16.00 then 16.8 like that what could it be and why.. and this time on my labs my mch is low 26.8
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Oct 24, 2011 @ 12:00 am
I've have elevated MCH for decades(just a few points elevated).
years ago I had a blood test for folic acid and B12.Results: folic and B12 above normal requirements.

I would like to solve the puzzle of why MCH are high. All other results are normal and so docs aren't interested.

Supplement I take daily: SAMe,and a combination supplement of B6. B12 and folic.
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Oct 31, 2011 @ 10:22 pm
i have a patient with neutrophil 4% , Lym 3.1% , Monocyte 0.58 , Eos 1.94 and Bas 0.09( the total of wcc(9.7) Rcc (3.9) Hb (116) Hct (0.37) MCV (96) MCH 30 MCHC 311 RDW 15.8 PLT 355 .
In the film Anisopiokiolocytosis (+)giant PLT (++) Acanthocyte(+) Burrcell (+)Fragmented (+)
the patient has the surgery progrss what is the diagnosis and what futher test should be done and what is the most prominent Feature and what is the most Probable Disorder. Thank you very much.
abu
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Nov 6, 2011 @ 12:00 am
what does normal red cell count but low haemoglobin mean..how is that possible.
Sapan
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Nov 12, 2011 @ 3:03 am
What is the problem if ESR is 25,RBC count is 4.02?
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Nov 23, 2011 @ 9:21 pm
i have megaloblastic anemia and was rushed to hospital with a h.b of 3.8 and rbc of 1.98 i was transfused 20ltrs over a few weeks my heamotologist has never seen it before my bone marrow biopsy was abnormal wit hyper segmented neurophils do u know any one else who has had it this bad? it came on quicky my hb was 11.2 in jan and went to 3.8 in feb?
Maya
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Dec 11, 2011 @ 9:09 am
What if my blood test show
Hemoglobin 11
Haematocrit. Pcv. 36.7
Rbcs 4.73
Mcv 77
Mch. 25
Mchc 33.2
Rdw-cv 15.8
Platelet count 412
Total leucocytic count 10.9

Neutrophils. 64
Lymphocytes 29
Monocytes 5.3
Eosinophils. 0.5
Basophils 0.5


Erythrocyte sedimentation rate
First hour. 16
Second hour 38



And the comment

Rbcs show hypochromia , microcytosis and anisocytosis



What this mean is it bad test
Manish SHarma
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Dec 17, 2011 @ 4:04 am
I m 24 years old, i just check my hemoglobin and my hemoglobin is 11.

so is it ok for my body if not than what i have to do.
lilian
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Dec 21, 2011 @ 9:09 am
My results are:

Haemoglobin 13.0
Red cell count 6.0
Total white cell count 7.3

Neutrophils 63.15%
Lymphocytes 24.93%
Monocytes 9.31%
Eosinophils 2.88%
Basophils 0.27%
Haematocrit 0.42
MCV 69
MCH 22
MCHC 31
Platelets 324

My doctor suggest i go for thalassarmia trait test.
Please advise
wendy daniel
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Dec 21, 2011 @ 5:17 pm
My daughter has a monocyte count of 17 she is 20 years old. She has been experiencing, fatigue, weakness, loss of weight (128 to 120 in a month), has low blood pressure, and has had one fainting spell. She is not trying to lose weight. Also, she has been complaining that her vision seems as though it is not as sharp. She eats a normal amount. The unexplained weight loss is the most troubling coupled with the fatigue. Is a monocyte count of 17 unusual?
suzanne
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Jan 18, 2012 @ 3:15 pm
Just got my resultsback. Is there anything I should concern myself about?WBC 5.93
RBC 4.56
HGB 14.8
HCT 43.7
MCV 95.8
MCH 32.5
MCHC 33.9
PLT 202
RDW-SD 42.2
RDW-CV 12.4
MPV 10.1
NEUT 3.19
LYMPH 2.22
MONO .45
EO .06
BASO .01
waqas
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Feb 7, 2012 @ 12:00 am
if you have macrocytic anemia it means that your red blood cells are large in size and it is mostly due to vitamin b12 or folic acid deficiency. you should take green leafy vegetables and vitamin b12 supplements
kathy
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Feb 9, 2012 @ 2:14 pm
I'm anemic for years up and down hemoglobin now its 10.8my red blood cells are low 3.5and my iron protein pottasiam calcium are all low had 200 units iron landed up in hosp swelled up within 45 min they said never hardly ever happens anyways going to see oncoligist the 16 could this be some kind of blood cancer
cynthia
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Feb 10, 2012 @ 7:07 am
Hi, I am a bit concerned about people who are on HAART and have elevated MCV and MCH yet Hb is normal. can this be due to drugs impact or is it because of diet intake? what is really happening to the indices?
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Mar 1, 2012 @ 2:02 am
pls can I get an explanation on why the heamoglobin concentration will be high and the red blood cell is very low
Myrna macalma
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Mar 20, 2012 @ 12:12 pm
Hi! Can u just tell me if I should worry on my 10 yr. daughter.All past other blood result always normal except this 3 components..MCV 65.9,MCH20.9,RDW 17.3..and first time her RBC 5.7, her hemoglobin is 11.9. Hoping for you quickreply. God bless
carolyn
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Jun 5, 2012 @ 11:11 am
Should I be worried if my RBC is always low but all other blood work numbers are within range. RBC is 3.8.
BANJOKO
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Aug 17, 2012 @ 7:07 am
MVC 78L
MCH 23.9L
MCHC 30.4L
NEUTROPHILS 38L
LYMPS 53H
NEUTROPHILIS ABSOLUTE 1.7L

MY JOINTS ACHE COULD IT BE LINKED TO MY FASTING TEST RESULT AND ANY RECOMODATIONS or SUPPLEMENTS TO USE.
THANK YOU
Mai
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Oct 23, 2012 @ 10:10 am
I have abnormally small RBCs but I am not anemic. The doctor doesn't know why this is. She had me tested for others but couldn't figure out why. Are there any other reasons for having small RBCs? Please advise. Thanks.
shabaan ahmed hassan
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Apr 27, 2013 @ 11:11 am
i need the answers of all questions in details & give me any web site about blood indices in details including case presentation with its answers
tariq mahmood
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May 10, 2014 @ 12:00 am
THE FOLLOWING LOW COUNT IN MY Blood CP Report
RBC:4.02
PCV:0.35
MCH:32.3
MCHC:36.7
Lymphocytes: 45

what is the this.
Elisabeth Smith
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Jun 5, 2014 @ 8:08 am
Can you check if this results are something to worry about?
MCHC 30.7 low
Lymphs 49 high
Phosphorus, serum 4.7 high
Lisa
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Aug 21, 2014 @ 3:15 pm
Hi I have been told I have macrocytosis ( nothing else really ?? ) with MCH 101.9
& MCV 33.9 ??
I also have factor v Leidon disorder , & I'm having problems with my lypmh nodes at present & I do not drink alcohol. Can anyone shed any light on this please.
Many thanks.

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