Complete Blood Count

(The complete blood count test is also known as CBC, Hemogram or CBC with differential.)

When is this test done?

This test is normally part of your regular medical work-up as a check on your general state of health.

It is a useful test for screening, diagnosing and managing all sorts of different diseases. It can highlight problems that have occurred because of a disease, show up an acute or chronic infection or an allergy.

What does it do?

It measures the numbers of the various types of cells found in your blood. Either increased or decreased numbers of different cells may suggest a problem, either one which may resolve itself or one which may require further tests and treatment.

How to prepare for the test.

There is no special preparation needed. Blood can be drawn at any time during the day and fasting prior to the test is not required.

Which parts of the blood are examined?

The CBC comprises a whole collection of different tests. Here I will list them and deal with general issues, then I will explain each test in greater detail on its own page.

Please read and understand the notes on this page, (both before and after the normal values list) about interpreting your own CBC results. Please do this before you jump off to the particular page you need.

Use the links in the list to jump to the page you need. Normal values for all the tests are included on their detail pages, and the full list of normal values is also presented below if that is all you need.

1. White blood cell (WBC) count
2. White blood cell differential, incorporating:-
. - - lymphocytes
. - - monocytes
. - - neutrophils
. - - eosinophils
. - - basophils
3. Red blood cell (RBC) count
4. Red cell distribution width (RDW)
5. Haemoglobin (Hg)
6. Hematocrit (HCT)
7. Erythrocyte (RBC) indices, incorporating:-
. - - Mean corpuscular volume (MCV)
. - - Mean corpuscular haemoglobin (MCH)
. - - Mean corpuscular haemoglobin concentration (MCHC)
8. The platelet count
9. Mean platelet volume (MPV)

Normal Values.

If you are not interested in anything other than finding out whether your test results are within specs then read no further than the list below.

However, remember that exact normal values for the different parts of the complete blood count are difficult to come up with as age, sex, and altitude can cause variations in some of them.

Also different labs and the different instruments used in them will have different principles of measurement that can result in widely differing 'normal' ranges. For example I have found 'normal' lab results for the Eosinophils count that range from 0 - 2% right up to 0 - 10%.

Obviously if you have an earlier result from the first lab of, say, 1% and then have a later test done at a lab that has a higher range, a result of, say, 7% is going to have you drawing up your will and calling the family to your bedside, when in actual fact you are well within their 'normal' range. Most labs will state their normal ranges and flag any of your results that fall outside them.

NOTE - One is used to mg for milligrams and such like symbols but there are a couple of symbols used in these tests that you may not have come across before. They are very, very small measurements and are :-
pg - picogram. This is one trillionth (0.000000000001) of a gram.
fl - femtolitre. This is one quadrillionth of a litre.

NB. Please also see the notes after the list below.

 

As a general average guideline:-

WBC - white blood cell count.

Adult Range:
SI units.
4.0 - 11.0 x 10*9 cells/L.
US units.
4,000 and 11,000 cells/ cu.mm (cubic millimetres) or /µl (per microlitre of blood)

WBC Differential.

Lymphocyte

Adult Range: 18 - 40%
Absolute value or Absolute lymphocyte counts (ALC):
720- 4400/µl or 0.72 - 4.4 x 10*9/L.
Children's Range: 25 - 50%
Absolute value or Absolute lymphocyte counts (ALC):
1000 - 5500/µl or 1.0 - 5.5 x 10*9/L.

Monocytes

Adult Range: 3 to 8%
Absolute value or Absolute monocyte count:
120 - 880/µl or 0.1 - 0.8 x 10*9/L.

Neutrophils

Adult Range: 50 - 73%
Absolute value or Absolute neutrophil counts (ANC):
2,000 - 8,030/µl or 2.0 - 8.0 x 10*9/L.
Children's Range: 30 - 60%
Absolute value or Absolute neutrophil counts (ANC):
1200- 6600/µl or 1.2 - 6.6 x 10*9/L

Eosinophils

Adult Range: 2 - 4%
Absolute value:
80 - 440/µl or 0.08 - 0.4 x 10*9/L.

Basophils

Adult Range: 0.5 - 1%
Absolute value:
20 - 110/µl or 0.02 - 0.1 x 10*9/L.

RBC - red blood cell count

(varies with altitude):
Male: 4.7 to 6.1 million cells/µl (per microlitre of blood)
Female: 4.2 to 5.4 million cells/µl
Children: 4.6 - 4.8 million cells/µl

Red cell distribution width (RDW)

11-15%

Haemoglobin

(varies with altitude):
Male - 8.1 to 11.2 mmol/L (13 to 18 gm/dL)
Female - 7.4 to 9.9 mmol/L (12 to 16 gm/dL)
Child - 7.1 to 8.4 mmol/L (11.5 to 13.5 gm/dL)
Newborns - 10.5 to 13.7 mmol/L (17 to 22 gm/dl)

Haematocrit

(varies with altitude):
Newborn Range - 0.5 to 0.62 (50-62%)
Child - 0.33 to 0.40 (33-40%)
Adult male - 0.39 to 0.51 (39-51%)
Adult female 0.34 to 0.46 (34-46%)

Mean Corpuscular Volume (MCV)

Values are higher in newborns and infants.
Adult men 80-98 fl (femtoliters)
Adult Women: 96-108 fl

Mean Corpuscular Haemoglobin (MCH)

27.5 - 33.5 pg/cell (picograms per cell)

Mean corpuscular haemoglobin concentration (MCHC)

32 to 36 gm/dL
(this is sometimes reported in % i.e. 32-36%)

The platelet count

The normal range can be expressed in a number of ways, but they all mean the same.
150,000 - 350,000/µl ( platelets per microlitre)
150,000 - 350,000/ mm3 (platelets per cubic millimetre)
150 - 350 x 10*9/liter.

Mean Platelet Volume (MPV)

7.5-11.5 fl

Note - when I set about gathering the information for the complete blood count I wondered if it was really necessary on a site proposing to deal strictly with diabetes. It is very rarely that any of the results of the tests have a direct connection with the disease of diabetes itself, unlike, say, the HgA1c or the Microalbumin tests.

However it eventually dawned on me that having diabetes did not prevent us from getting other diseases (if only it did - at least then there might be some benefit to having it!).

In fact it often left us open to catching something else and therefore any information that can lead to early detection and treatment of these secondary issues is a bonus. This is one of the invaluable assets of the CBC and so I have included it.

NB
I have said this before but it is important so I am going to keep on stressing it.

Do not take a look at the results of your CBC, see results that do not appear to be within the ranges given on this site and go into a decline, imagining your immanent death from some dire disease.

Anything that appears unusual needs to be discussed with your doctor who will be far more able to correctly interpret the results.

You know what most of us are like - we always see the worst case scenario. It is like reading a medical encyclopaedia, you are convinced you have every disease in the book.

Yes, a high WBC does mean you could have leukaemia but it is far more likely to indicate something as simple as a tooth abscess - painful but not exactly life threatening!

My very first set of lab results that were done after the diagnosis of diabetes came back flagged for a lymphocyte count of 7 x 10*9/L, way over that labs normal range of 0.72 - 4.4 x 10*9/L.

I could have had all sorts of diseases with fancy unpronounceable names, like Toxoplasmosis or Mononucleosis, but in actual fact I was recovering from an abscess that developed from a simple insect bite (oh the joys of undiagnosed diabetes!).

So see your medical practitioner!!!

If you are still worried ask to have another set of tests done to compare results. If necessary say you want a second opinion or try another doctor.

 


Back to top