A serum hemoglobin test measures how much hemoglobin is circulating freely in your serum. Serum is the yellowish fluid with no blood cells or clotting factors. Hemoglobin is a type of protein that transports oxygen into tissues.
Usually, the whole hemoglobin in your body is in your red blood cells. While, certain conditions may lead to some hemoglobin to be in your serum. This is referred to as free hemoglobin. Serum hemoglobin test measures these free hemoglobins.
Physicians frequently use this test to diagnose or monitor abnormal red blood cell degradation. If you have recently received a blood transfusion, this test may detect a transfusion response. One other cause could be haemolytic anemia. If you get that kind of anemia, your red blood cells break down too quickly. This causes more free hemoglobin in your blood.
In some cases, the test is used as a blood hemoglobin test.
Why do I need a serum hemoglobin test?
Your physician may request a serum hemoglobin test if you show symptoms of hemolytic anemia. This happens when your red blood cells break down rapidly and your bone marrow cannot replace them quickly enough.
Your doctor may also carry out this test if you have been previously diagnosed with haemolytic anemia. If this is the case, it may help your doctor monitor your condition.
What Is Hemolytic Anemia?
Two types of hemolytic anemia exist.
Extrinsic hemolytic anemia
If you suffer from extrinsic hemolytic anemia, your body produces normal red blood cells. However, they are destroyed too quickly due to infection, an autoimmune disorder, or a particular type of cancer.
Intrinsic hemolytic anemia
If you suffer from intrinsic hemolytic anemia, your red blood cells themselves are faulty and their degradation happens very quickly. Sickle cell anemia, thalassemia, congenital spherocytic anemia, and G6PD deficiency are any conditions that may cause hemolytic anemia.
The two types of heemolytic anemia are responsible for similar symptoms. However, you may experience extra symptoms if your anemia is due to an underlying condition.
Early stages of hemolytic anemia may involve:
You can also suffer from headaches.
As the disease develops, you will experience more serious symptoms. Your skin can turn yellow or pale, and your eye sclerotic can turn blue or yellow. Additional symptoms include the following:
- brittle nails
- heart problems (an increased heart rate or heart murmur)
- dark colored urine
- an enlarged spleen
- an enlarged liver
- soreness in tongue
How is the test carried out?
A serum hemoglobin test requires a small amount of blood to be taken from your hand or arm. This process usually takes just a couple of minutes:
- Your health care professional will apply an antiseptic to the area of your blood collection.
- A rubber band will be attached around your arm to increase the amount of blood flow to the veins, making them swell. It makes it easier to locate a vein.
- Next, a needle will be placed in your vein. Once the vein is punctured, the blood circulates through the needle into a small tube that is attached. You may experience a small sting when the needle is inserted, but the test itself does not hurt.
- After the blood is taken, the needle will be removed and a sterile bandage will be applied to the injection site.
The blood collected is then sent to a laboratory where it can be analysed.
Serum Hemoglobin Test Results
Serum hemoglobin is reported in grams of hemoglobin per decilitre of blood (mg/dL). Since the laboratory results are different, your doctor will help you determine whether your results are normal or not. If your results return to normal, your doctor may want to carry out additional tests.
Elevated hemoglobin levels in your serum are usually indicative of hemolytic anemia. Conditions which may cause abnormal red blood cell degradation include, but are not limited to:
- sickle cell anemia: a genetic condition that causes your red blood cells to be hard and abnormally formed.
- G6PD deficiency: when your body does not produce enough enzyme to produce red blood cells)
- hemoglobin C disease: a genetic disease that produces abnormal hemoglobin.
- thalassemia: a genetic disease that affects your body’s ability to generate normal hemoglobin.
- congenital spherocytic anemia: a disorder of the membranes of your red blood cells, which have the form of a sphere.
If there are any abnormalities in your test results, your health care provider is likely to do more testing to identify the exact cause of your hemolytic anemia. These extra tests can be simple blood and urine tests, or You may need to test your bone marrow.
Risks of the Serum Hemoglobin Test
The only risks involved in this test are those still associated with blood collection. For example, you may experience minor pain when the needle is inserted to collect your blood sample. You may experience some bleeding when the needle is removed or develop a small contusion in the area.
Rarely, the results of a blood test can be more serious, like excessive hemorrhage, fainting or infection at the injection site.