Primus Pathology Laboratory

Hemoglobin Test

Last Updated on July 28, 2022 by Dr. Neeraj Gujar


A hemoglobin test is used to measure hemoglobin levels in the blood. Hemoglobin, a protein found in red blood cells, is responsible for carrying oxygen from your lungs into your body. A high hemoglobin level could indicate a blood disorder.

The hemoglobin test measures the amount of hemoglobin in your red blood cells. Your bone marrow produces Hgb, which is stored in your red blood cells. It aids red blood cells to transport oxygen through your arteries from your lungs.

It also transports carbon dioxide, CO2, from your body to your lungs via your veins. Red blood cells are made of Hgb.

An abnormally high or low level of Hgb can lead to symptoms such as exhaustion or dizziness, or shortness of breath. If you experience these symptoms, your doctor may recommend a Hgb test. There may be an underlying condition you need to be diagnosed with.

Why Test Is Done?

The hemoglobin test is used to diagnose anemia. This is a condition where your body has fewer than normal red blood cells. Anemia is a condition in which your body doesn’t have enough oxygen. A complete blood count (CBC) measures hemoglobin level.

Hgb testing may be ordered as part of a Complete Blood Count (CBC) test. The CBC test can also measure other vital components of your blood like white blood cells or platelets. An abnormal level of any one of these cells could indicate an underlying condition or disorder.

When To Get Tested?

The test may be ordered by your health care provider as part of a routine examination, or if you are already undergoing:

  • Anemia symptoms include weakness, dizziness, and cold hands or feet.
  • A family history of Thalassemia, Sickle Cell Anemia, or another inherited blood disorder
  • Long-term infections
  • Low in iron or other nutrients
  • Excessive bleeding after a surgery or injury

Symptoms of Low Hemoglobin Levels

Low Hgb, also known as anemia is a condition where you don’t have enough blood cells.

Anemia can also be confirmed by a blood test. This will show you if your red cell count is low and if you have low hemoglobin. This is the ratio of your red blood cells to other components.

Anemia can be caused by many different factors, so symptoms may vary. Anemia symptoms include:

  • Exhaustion
  • Skin paleness
  • Pain in your chest
  • Breathing difficulty
  • Headache
  • Abnormal or quick heartbeat
  • Problems with physical activity
  • Cold, swollen hands or feet

Although fatigue and exhaustion are not symptoms of low hemoglobin levels, they can be. Low hemoglobin levels can cause decreased oxygen delivery to vital organs, muscles, and ultimately fatigue.

Symptoms of High Hemoglobin Levels

Polycythemia is a form of high Hgb. This is when you have too many red cells.

Polycythemia Vera refers to a form of cancer in which the red blood cells are produced more efficiently by your bone marrow than by your blood. A blood test can also be done to confirm that you have polycythemia.

High levels of Hgb can be characterized by the following symptoms:

  • Itching
  • Dizziness
  • Headache
  • Easy bleeding
  • Painful joint swelling
  • More sweating than usual
  • A yellow tint to the eyes or skin (jaundice)
  • Abnormal weight loss
  • A purple- or reddish hue to the skin
  • Feeling exhausted

Also Read: How Do Doctors Use Iron Test to Diagnose Anemia or Hemochromatosis?

How To Get Tested?

A hemoglobin test does not require any preparation. Fasting may be required if your doctor has ordered additional tests for your blood sample. If there are special instructions, your health care provider will inform you.

During the Test

A small needle is used by a health professional to take blood from a vein on your arm. Once the needle has been inserted, some blood will be taken and stored in a vial or test tube. The needle may cause a slight stinging sensation when it is inserted or removed. It usually takes less than five minutes.

After The Test

A blood test is not a risky procedure. Some people may experience mild pain, dizziness, or bruising after the test. These symptoms typically disappear quickly.

Test Results

Your age and gender both affect your Hgb levels. Typical healthy Hgb levels are as follows:

CategoryHgb level, in grams per deciliter (g/dL)
young children11.5–16.5
adult males13–16.5
adult females (not pregnant)12–16
adult females (pregnant)11–16

Hgb levels for men below 13 g/dL can be considered low. If you are not pregnant, Hgb levels for women below 12 g/dL will be considered low.

This threshold can change depending on certain conditions. This threshold can vary from one lab to another, so make sure you check the reference range. These levels can also change depending on the age of children, particularly infants younger than 6 months.

Interpreting Results

There may be many reasons why your hemoglobin levels are not normal.

Low hemoglobin levels could be an indication of:

  • Different types of anemia
  • Thalassemia
  • Iron deficiency
  • Liver disease
  • Cancer, and other diseases

A sign of high hemoglobin levels could be:

  • Lung disease
  • Heart disease
  • Polycythemia vera is a condition in which your body produces too many red blood cells.

It doesn’t necessarily mean that you have a medical condition. The results can be affected by diet, activity, medications, menstrual cycle, and other factors. If you live in an area with a high altitude, your hemoglobin levels may be higher than usual. Discuss your results with your provider.

Causes of Low Hemoglobin Levels

Any condition that reduces the body’s ability or makes it less efficient at creating red blood cells can lead to low levels of Hgb.

Low Hgb could be caused by:

  • Insufficient iron in your diet makes it more difficult for your bone marrow Hgb production.
  • Insufficient folate or vitamin B-12 can cause your body to produce fewer red blood cells that are necessary.
  • Severe bleeding after surgery or major injury.
  • Internal bleeding from stomach ulcers, stomach, colon cancer, and other internal injuries
  • Sickle cells anemia is a genetic condition that causes red blood cells in the body to have abnormally sickle-shaped red blood cells and to be able to carry less Hgb
  • Hypothyroidism is a condition in which the thyroid gland does not produce enough thyroid hormones.
  • splenomegaly or an enlarged liver due to infection, liver conditions, or cancer
  • Bone conditions such as Leukemia that stop your bone marrow from producing enough red blood cells are bone-marrow conditions.
  • Chronic kidney disease in which your kidneys stop functioning (resulting from a lack of erythropoietin – a hormone that stimulates the production of red blood cells in your bone marrow).

You might also be affected by:

  • Don’t donate blood too often
  • Heavy bleeding during your period
  • Alcohol misuse
  • Chronic health issues such as cancer or autoimmune diseases can be a problem.

Causes of High Hemoglobin Levels

Your body may store more Hgb in red cells because of your environment. This could be a problem that can affect your heart, lung function, lifestyle choices, and other factors.

High levels of Hgb could be due to:

  • Living at high altitudes, where oxygen is scarcer than in the mountains
  • Smoking tobacco products (including cigarettes or cigars)
  • Chronic obstructive lung disease (COPD), is a condition that inflames your lungs and prevents air from reaching your lungs
  • Lung diseases and heart problems can affect your ability or ability to breathe, the ability of your lungs to carry oxygen into your bloodstream, or your heart’s ability to pump normally.
  • Taking erythropoietin unnecessarily, to enhance high-level physical performances

There are also other causes:

  • Being severely dehydrated
  • heart failure
  • Cancer of the liver, or kidneys

Final Takeaway

If you have signs of abnormal Hgb levels, or if your doctor suspects you are pregnant, your doctor may recommend Hgb testing.

You have a better chance of achieving successful treatment if you recognize the signs and symptoms of abnormal Hgb levels as soon as possible.

If you have symptoms of high or very low Hgb, consult your doctor. You will need to have regular Hgb testing and a CBC if you have a history of blood disorders or conditions that affect bone marrow production.

While some forms of anemia may be mild, others can be severe and even life-threatening. Talk to your doctor if you have been diagnosed with anemia.


Why do doctors test hemoglobin?

Doctors will order a hemoglobin test to check for low or high levels of red blood cells. They might do this as part of a routine checkup to screen for problems or if you aren’t feeling well. 

How can I raise my hemoglobin fast?

If you are looking to increase your hemoglobin levels, include these foods in your diet:

  1. Meat and fish.
  2. Eggs.
  3. Dried fruits, such as dates and figs.
  4. Soy products, including tofu and edamame.
  5. Broccoli.
  6. Green beans.
  7. Green leafy vegetables, such as kale and spinach.
  8. Nuts and seeds.
What foods to avoid if you have low hemoglobin?

You should try to avoid milk and other dairy products. Also stay away from foods that contain tannins like grapes, corn, and sorghum. Apart from that keep your distance from foods that contain phytates or phytic acids, such as whole-grain wheat products and brown rice.

by Dr. Neeraj Gujar

Dr. Neeraj Gujar has done his M.D. in Pathology from Government Medical College. He has worked at various organisations such as Breach Candy Hospital and Tata Memorial Hospital along with many other private organisations. During his working career, he realised the pressing need for exceptional quality diagnostic services. A diagnostic centre that can consistently give accurate results verified by a consultant doctor (M.D. Pathologist) on which your doctor can depend. This has been the founding principle of Primus Pathology and Diagnostics.

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