How do I Read My Hemogram Test or CBC Lab Report?

Posted On June 8, 2021January 27, 2023

Introduction

Want to know about the hemogram test report? 

Whenever we get sick and visit the doctor for a check-up. Our first test in a doctor’s prescription is a complete hemogram test or CBC (Complete Blood Count) test.

A hemogram test is one of the important diagnostic medical tools that help to find out various disorders, including anemia, infection, inflammation, allergies, and leukaemia. 

This test provides information on the quality, quantity, size, and shape of your blood count. 

A hemogram test report also gives an idea to diagnose your disease. 

When you receive your hemogram report, your report will show two columns: a “reference range” and your results. 

You can consider your results normal if they’re within the reference range. And your results would be abnormal if they differ from the reference range. 

Your hemogram results should be clinically correlated with your symptoms. This hemogram test tells your current health status and helps your doctor to identify the disease. 

This post will discuss the crucial parameters (such as PCV, MCV, MCH, MCHC, DLC, etc.) of the hemogram or CBC test.

Moreover, we will interpret the hemogram results. 

What is a hemogram test, and what is it used for?

A hemogram is a medical laboratory test that analyses the complete blood count. It is one of the most routine laboratory blood tests. 

This laboratory test is often recommended when you get sick or struggle with symptoms like fever, weakness, sore throat, shortness of breath, pain, etc.  

The main purpose of this blood test is to check your overall health and identify a wide range of disorders including anaemia, allergies, infection, inflammation and leukaemia. 

Overall, a hemogram test help to find the cause of the disease or your symptoms. 

What is the difference between a hemogram and a CBC test?

A Complete Hemogram test is also known as a complete blood count (CBC) or full blood count test. 

A hemogram and CBC test are generally the same blood test, but there is a slight difference between these two tests. 

In the hemogram test, you can find the complete blood count (CBC) results with ESR (Erythrocyte Sedimentation Rate). While CBCs only include full blood count results without ESR.

Here, ESR is used to identify the inflammation problem. 

This is the only difference between a hemogram and a CBC test. 

How is the hemogram test done?

A Complete hemogram is basically a simple blood test. 

You need to give 3 ml of blood for the hemogram test or 1 ml for the CBC test. 

The blood sample is taken in a purple tube. This purple tube contains a chemical called EDTA.

EDTA is basically an anticoagulant property that helps to prevent the clotting of blood. 

After taking the blood sample, this purple tube is put into a haematology analyser. 

This analyser gives complete reading about your blood counts. 

What is included in the complete hemogram test list?

The CBC test evaluates your whole blood counts value, including RBC (Red blood cells), WBC (White blood cells), and Platelets.

You may also get the reading of crucial parameters of blood counts such as – 

Red blood cell indices 

• Mean Cell Volume (MCV)
• Mean Cell Haemoglobin (MCH) 
• Mean Cell Haemoglobin Concentration (MCHC)
• Haemoglobin content 
• RBC Distribution Width (RDW) 
• Packed Cell Volume (PCV) OR Haematocrit (HCT)

Complete white blood cells count 

• TLC (Total Leukocyte count) 
• DLC (Differential Leucocyte count) – Neutrophils, Eosinophils, Basophils, Lymphocytes and Monocytes. 

Platelet count and indices 

• Platelet count
• Mean Platelet Volume (MPV)
• Platelet Crit (PCT)
• Platelet Distribution Width (PDW) 

Moreover, the hemogram test determines the ESR (Erythrocyte Sedimentation Rate) value. 

What do red blood cell indices indicate in hemogram tests?

When you get your blood test report, you might have seen such values as PCV, RDW, MCV, MCH and MCHC. 

These parameters (PCV, RDW, MCV, MCH and MCHC) are called red blood cell indices. 

Let’s understand each RBC indices separately – 

PCV in Blood Test

Have you ever tried to know PCV meaning in blood test reports? 

Blood is an essential biological fluid that constantly circulates in your body through blood vessels. It is a combination of cells (RBC, WBC & platelets) and plasma.  

Suppose you give a 1 ml blood sample for a blood test. If you centrifuge your blood sample, you will see three layers in the test tube.

These three layers represent – 

• Top layer (yellowish colour) – Plasma
• Middle layer (yellowish-brown) – Buffy coat (White blood cells and platelets)
• Lower layer (dark red) – Red blood cells (erythrocytes)

In this 1 ml blood sample, you will get 0.45 ml red blood cells (RBC) that aggregate at the bottom of a test tube. 

If we calculate red blood cells in proportion, it would be 45% of the total blood sample. 

The percentage or volume of red blood cells represents Packed Cell Volume (PCV), also known as haematocrit value.  

• PCV normal value = 45% (0.45 ml) 
• PCV normal range for men = 40 to 54%
• PCV normal range for women = 36 to 48%

PCV low means you don’t have enough red blood cells in your body, indicating anemia. 

Due to this anemia, you may feel lethargy, weakness, shortness of breath, yellowish skin and headache. 

It would help if you correlated with other blood parameters. 

Red Blood Cell Count in Hemogram Test

The Red Blood Cell Count represent the number of red blood cells in a given sample. 

Generally, a 1 ml blood sample contains 5 million RBCs. 

The normal red blood cell value is 5000000/ml. 

The primary function of your red blood cells is to transport oxygen from the lungs to the body’s tissues. 

Suppose you have less RBC count (3000000/ml) in your blood, which represents anemia. But you need to correlate with other laboratory parameters (like MCV, MCHC, RDW) to find the type of anaemia. 

Conversely, too many RBC count (7000000/ml) represents erythrocytosis. The main causes of erythrocytosis are polycythemia vera, heart disease, lung disease etc.  

MCV in blood test 

The MCV full form is Mean Cell Volume. It represents the average volume occupied by one red blood cell. 

To know the size and volume of one RBC in a healthy person, you need to check the MCV value. 

MCV generally calculates by – 

MCV=PCV/Total RBC count

MCV = 0.45/5000000 = 90 x 10^-15 L

= 90 femtolitre (FL)

The MCV blood test normal range is 90 ± 10 FL, indicating the normal shape. The normal shape of RBC is called Normocytic. 

It means the range of MCV values usually is between 80 FL to 100 FL. 

Now, you can read the MCV value easily in your CBC report. For example, 

Normal MCV range 

• MCV = 80 to 100 FL (Normocytic – Normal MCV)

Abnormal MCV level 

• MCV high means large RBC shape, called Macrocytosis. It generally happens if your MCV level is more than 110 FL.
• MCV low means small RBC shape, called Microcytosis. It generally happens if your MCV level is less than 80 FL.

Hb Range in CBC Lab Report

You must have seen the Hb value in your blood test report. 

Hb indicates haemoglobin. The leading role of hemoglobin is to deliver oxygen to all tissues. 

Generally, each RBC contains some amount of haemoglobin. RBC is like a bag of haemoglobin but is not 100 % full. 

A healthy person may get 33 % haemoglobin content in one RBC.  

To know the haemoglobin content in total RBC, you may calculate by PCV. For example, 

Suppose the normal PCV value is 0.45 ml.

Then, 33% of PCV will be the total haemoglobin content = 0.45/3 = 0.15 ml 

A unit of hemoglobin measurement is grams per deciliter (g/dl). So, the normal range of haemoglobin will be 15 gm/dl.

It generally varies in different age groups – 

• Hemoglobin normal level for male = 14 to 18 g/dl
• Hemoglobin normal level for female = 12 to 16 g/dl
• Hemoglobin normal level in pregnancy = 12 to 16 g/dL
• Hemoglobin normal level for newborn = 14 to 24 g/dl
• Hemoglobin normal level for 6-18 years children = 10 to 15.5 g/dl

MCH in blood test

The MCH full form is Mean Corpuscular (or cell) Haemoglobin. 

To know the amount of haemoglobin in one healthy RBC, you must see the MCH value. 

It can be calculated by – 

MCH=Total Hb content/Total RBC count

MCH = 15/5000000

=30 Picograms (Pg) 

Here, MCH 30 Pg is normally present in a healthy RBC. You can find the normal MCH value (30 Pg) in a healthy person’s CBC Lab Report.

MCHC blood test

The MCHC full form is Mean Corpuscular (or cell) Haemoglobin Concentration.

The MCHC value tells the degree of haemoglobin juiciness in a single RBC.

If you want to know the haemoglobin concentration (or % of Hb) in one RBC, then check the MCHC value. 

It can be calculated by –

MCHC= Total Hb content/PCV

MCHC = 15/0.45 =33%

You can find the average MCHC value (33 %) in a healthy person’s CBC lab report. 

The normal MCHC value represents a Normochromic RBC. It means you have an average degree of hemoglobinization (or normal red colour RBC).

If you find the MCHC value low (i.e., 20%) in your blood test report, then it indicates Hypochromic RBC.

Conversely, if you find the MCHC value high (i.e., 50%), then it indicates Hyperchromic RBC.

Therefore, MCHC is an important laboratory parameter in diagnosing the anaemic condition.

RDW in CBC blood test 

RDW is also a significant laboratory parameter in diagnosing anaemia.  

Here, RDW stands for RBC Distribution Width. Basically, RDW tells the variation in the size of RBC. 

You can see the RDW value in percentage or Bell-shaped graph form. 

The RDW normal range is 12 to 15%. Suppose your RBCs do not vary by 12 to 15%. In that case, medically, it is called anisocytosis (red blood cells are not similar in size). 

You can see the abnormal value of RDW in iron deficiency anemia. 

RDW normally correlate with MCV. 

Suppose your MCV value is 60 FL in the blood report. In that case, you will see a narrow bell-shaped curve with less than 12% RDW value. It indicates Microcytic anaemia (RBCs shape is very small). 

MCV 60 FL + 7% RDW value (or Narrow bell-shaped curve) = Microcytic anaemia

Microcytic anaemia is generally happened due to iron deficiency anaemia.  

Conversely, if the MCV value is 110 FL and the Bell-shaped curve is too wide with more than 15 % RDW value. It indicates Macrocytic anaemia (RBCs shape are very large).

MCV 110 FL + 22% RDW value (or Wide bell-shaped curve) = Macrocytic anaemia

Macrocytic anaemia generally happens due to Vitamin B12 deficiency anaemia or Vitamin B9 (or folic acid) deficiency. It is also called Megaloblastic Macrocytic anaemia. 

How do you interpret MCV MCH and MCHC?

Normally, red blood cells are biconcave disc-shaped. It becomes abnormal during anemia.

Suppose you got a lesser number of red blood cells (25000000/ml) in your blood report; it would indicate anemia.

But RBC count would not help in determining the type of anemia.

You might have also seen MCV, MCH and MCHC values in your blood test report. This value helps your doctor identify the type of anemia.

Here, I have mentioned the different CBC test report images that help in determining anemia types – 

What is TLC in a blood test report?

In the hemogram test, TLC full form is total leucocyte count. 

TLC is also known as WBC (or white blood cells). The main function of TLC is to protect your body from infection (or foreign invaders). 

The purpose of the TLC test is to know the underlying cause of the disease. 

If we talk about TLC count, you can observe a normal TLC range of around 4,000 to 11,000 counts in 1 ml of a blood sample.

The normal range of TLC also varies in different age groups – 

• TLC normal range in new-born baby = 9,000 to 30,000 cells/ml 
• TLC normal range in children aged 2 years or below = 6200-17,000 cells/ml
• TLC normal range in over 2 years and adult = 4,000 to 11,000 cells/ml 

Your TLC count becomes dangerous if more than 11,000 cells/ml indicates Leukocytosis and lower (<4,500 cells/ μL) than the normal range called Leukopenia. 

It can be more critical if less than 500 cells/ml indicates the risk of life-threatening infections. If it is over 30,000 cells/μL means massive illness or severe disease such as leukaemia.

If you have a low WBC count, then you can’t fight against infection. Leukopenia is strongly associated with AIDS, HIV, dengue, malaria, aplastic anemia, and other immunocompromised diseases. 

What is DLC in the blood test report? 

In the hemogram test, DLC full form is Differential Leucocyte Count. 

In the CBC report, differential leucocyte counts (DLCs) indicate the proportion of different types of white blood cells.

White blood cells (or TLC) are divided into two basic categories – granulocytes and non-granulocytes.

Granulocytes are those cells that contain granules (or small particles), and it releases during infection, inflammation, and allergies. It includes neutrophils, eosinophils and basophils. 

While agranulocytes do not contain granules in their cytoplasm. It includes monocytes and lymphocytes. 

Let’s discuss each DLC cell – 

Neutrophils 

The most abundant white blood cells in our blood are Neutrophils. Your blood test report shows that the normal percentage of Neutrophils is 40 to 75%.

If your neutrophil count is higher than 75%, that indicates Neutrophilia. 

Generally, Neutrophils count gets an increase in recent onset inflammation for a short duration. 

Neutrophilia can also be seen in infection, which produces pus like staphylococcus and streptococcus infection in sore throat, pharyngitis tonsilitis, etc. 

In contrast, if your neutrophils are lower than 40%, that indicates Neutropenia. It commonly happens in viral infections. 

Eosinophils 

Eosinophil counts are less abundant in our blood. The blood report shows normal eosinophils count of around 1-6 %.  

If your eosinophils count is higher than 6% in your CBC, that indicates Eosinophilia. 

Your eosinophils count increases when you are exposed to any parasitic infection or allergic reactions. 

Sometimes, you might see fewer eosinophils count (<1%) in your blood report that indicates Eosinopenia. It is commonly seen in sepsis, Cushing syndrome and long-term use of steroids. 

Basophils 

Basophils usually are present in around 0-2% of white blood cells. The higher basophil count (more than 2%) indicates Basophilia. 

You can see higher basophils count if you have an immediate type of allergic reaction (or Type-1 hypersensitivity).

Monocytes 

Monocytes are just like a type of phagocyte. These cells find the germs (or micro-organisms) and destroy them.  

Your blood report shows a normal monocyte count of around 2 to 10%. 

More than 10 % of monocytes indicate Monocytosis. It is classically seen in chronic infections (or long-term infections) like tuberculosis, HIV etc. 

Lymphocytes 

Lymphocytes are the main army of your immune system. 

When any microbes or foreign particles enter your body, these cells fight with them and protect your body. 

Lymphocytes have two main types –

• T-Lymphocytes (also called T cells or Natural killer cells), and
• B-Lymphocytes (also called B cells)

B- Cells help produce antibodies, while T-cells directly kill the micro-organism. 

The normal lymphocytes are present in 15 to 40%. 

If you find an increase (more than 40%) in lymphocyte count in the CBC report, it indicates Lymphocytosis. It is mostly seen in viral infections and chronic infections. 

On the other hand, if you observe a low lymphocyte count (less than 15%) in your CBC report, it indicates Lymphocytopenia. It is mostly seen in HIV, autoimmune disorders and undernutrition conditions. 

When should I worry about my platelet count? Or What causes abnormal blood platelets?

The primary function of platelets is to stop bleeding. If you get injury or inflammation, platelets help to make a clot to prevent bleeding. 

Although, platelets can slightly increase during inflammation. It can be a concern if there is damage to your blood vessels. In this circumstance, your body increases the platelets count from the normal range and deposits in the damaged area that makes a clot. 

In adults, the normal platelet count ranges from 150,000 to 450,000 counts per ml of blood.

If your platelet count is more than 4,50,000 per ml, it is called thrombocytosis, which can lead to a risk of clotting. 

It can also elevate in – 

• Heart disease by atherosclerosis
• Myeloproliferative disorders (bone marrow makes too many blood cells)
• Infection
• Iron deficiency anemia and hemolytic anemia 
• Inflammatory illnesses like rheumatoid arthritis, IBD (Inflammatory bowel disorder)
• Cancer

If there is an unknown cause of high platelet count is called thrombocythemia. 

It may be life-threatening if your blood platelet count is below the normal range (<1,50,000), leading to the risk of bleeding. The lower platelet count is called thrombocytopenia. 

It is most commonly seen in dengue, malaria, typhoid, viral infection, vitamin B12 deficiency, leukemia, anemia, autoimmune disease, etc.

Also read, Best foods to increase platelet counts

What is ESR in the hemogram test? 

ESR is a strong inflammatory marker in your hemogram test report. This parameter tells the information about inflammation. 

The ESR full form is Erythrocyte Sedimentation Rate. It measures the sedimentation rate of red blood cells in a test tube. 

If I say simply, This ESR test shows how quickly the number of red blood cells falls in one hour. 

• ESR normal value in men = 0 to 15 mm/hr 
• ESR normal value in women = 0 to 20 mm/hr 

Suppose you got a high ESR value (80 mm/hr) that indicates inflammation in your body.

High ESR means your red blood cells are falling too fast than normal. 

It generally happens when the fibrinogen level is high. 

In our blood, there is a protein called fibrinogen. The crucial role of fibrinogen is to make blood clot that helps to prevent bleeding. 

It is just like glue. If the fibrinogen value is high, it will stick to red blood cells and increase the sedimentation rate. 

So, inflammation depends on fibrinogen and should be in a normal range.  

Whenever your immune system gets aggressive during infection, it destroys the tissue that causes inflammation. 

In this condition, if you observe your ESR blood test report, you will see a high ESR value. This high ESR value represents you have inflammation in your body. 

ESR is generally increased in arthritis, autoimmune disease, renal disease etc. 

High ESR values can also be seen in physiological conditions like pregnancy and older people. 

What is CRP test used for?

Suppose you want to know the confirmation of inflammation or infection. In that case, you must check the CRP value in your hemogram blood test. 

In the blood test report, CRP’s full form is C-Reactive Protein. 

CRP normal range is 0.8 to 1 mg/dl; it may vary from lab-to-lab report.

CRP is present in your blood but released from the liver. During inflammation or infection, the CRP level gets high. 

High CRP is a classical sign of acute inflammation, but it also gives information about past inflammation (or chronic infection).

It is generally correlated with ESR and other clinical symptoms. 

Conclusion 

A hemogram test does not reflect any particular disease. This is a helping tool to identify and diagnose the medical condition.

Your doctor may correlate the hemogram or CBC report with your symptoms, medical history, current medication, and other factors. 

It can be used in regular health check-ups. 

It is the only informative article. 

Here, I have explained every hemogram parameter. Now, you can read your hemogram blood test report easily.

If you have any doubts regarding this post, please let me know by leaving a comment below.

FAQ

Q 1. Can CBC detect blood infection?

Yes. CBC is a valuable laboratory blood test to detect blood infection. You need to check your TLC count. If the TLC count is high, you have an infection. Conversely, low TLC means you are more susceptible to getting an infection. 

Q 2. Is fasting required for Haemogram?

Although, there is no strong recommendation for fasting for a hemogram test. But as per a study, food intake might impact some CBC parameters like WBC counts. Therefore, giving a blood sample in 12 hours of fasting would be best for accurate results. 

Q 3. Is hemogram and hemoglobin same?

No. Hemogram and hemoglobin are not the same. Hemoglobin (Hb) is a blood parameter of the hemogram test. 

Q 4. What color tube is hemogram?

A purple color tube is used for a hemogram or CBC test. This tube contains a chemical called EDTA that helps to prevent blood clotting. 

Q 5. What is the cost of complete Hemogram test?

The complete hemogram test is relatively inexpensive. The cost of a hemogram test varies in different cities. If your doctor advises CBC, you have to go to the pathology lab and give the blood sample. After a few hours, you will get your CBC result. 

Sources –

1. Reinhold munker et al. Modern hematology. Biology and clinical management, 2nd edition. Humana press, new jersey, 2007. Chapter -1, 2, 5, and 7.
2. The Etiology and Management of Leukopenia
3. Drugs induced neutropenia
4. Complete blood count
5. Megaloblastic Anemia and Other Causes of Macrocytosis
6. Complete blood count. Wikipedia

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