The Role of Anemia Testing
Routine blood testing, such as during a medical check-up, may reveal anemia in patients who have mild cases with few or no symptoms.
In people who have symptoms, diagnostic anemia testing can determine whether red blood cells are diminished. In-depth analysis of the blood often helps with finding the type and cause of anemia.
Because anemia is a blood disorder, most tests use a blood sample. However, doctors may need to check for different potential causes, which can involve other types of testing.
Types of Anemia Tests
The complete blood count (CBC) is an essential part of anemia testing. This test measures different types of cells in the blood. It is often used as part of a routine check-up and in diagnosing health problems, and it can reveal the presence of anemia.
The CBC analyzes the amount of various blood cells as well as a protein called hemoglobin in the blood. Other tests, described in the following tables, may be prescribed depending on your CBC results, symptoms, and health history.
Additional tests can help identify the type and cause of anemia, but most patients do not need extensive testing. Your doctor is in the best position to address which tests are most relevant in your situation.
Because anemia is a blood disorder, various tests, such as those in the table below, can be used to do an in-depth analysis of different components of the blood. Tests like a blood smear, white blood cell differential, and reticulocyte count can often help assess anemia after an abnormal CBC. Other listed blood tests may be warranted in more specific circumstances:
TESTS RELATED TO BLOOD CELL TYPES, COUNTS, AND FUNCTION | ||
---|---|---|
Test Name | Test Sample | What It Measures |
Blood smear | Blood | The number, size, and type of different blood cells |
Differential | Blood | The number of different types white blood cells |
Reticulocyte count | Blood | The number of reticulocytes, which are newly formed red blood cells |
In some types of anemia, red blood cells are destroyed faster than they can be replaced. The following tests may be used to measure an abnormal breakdown of red blood cells:
TESTS RELATED TO INCREASED DESTRUCTION OF RED BLOOD CELLS | ||
---|---|---|
Test Name | Test Sample | What It Measures |
Hemoglobinopathy evaluation | Blood | The amount of different types of hemoglobin, a protein in red blood cells |
Haptoglobin | Blood | A protein that can reflect destruction of red blood cells |
Lactate dehydrogenase (LD) | Blood | An enzyme that can be a sign of tissue damage and red blood cell destruction |
Osmotic fragility test | Blood | The vulnerability of red blood cells to breaking apart |
G6PD | Blood | An enzyme that helps prevent red blood cells from breaking apart |
Direct antiglobulin test | Blood | Whether red blood cells are being attacked by antibodies of the immune system |
Anemia can occur because of unidentified blood loss. When this cause is suspected, tests such as those in the table below may look for signs of blood loss especially in the gastrointestinal system:
TESTS RELATED TO POTENTIAL BLOOD LOSS | ||
---|---|---|
Test Name | Test Sample | What It Measures |
Fecal occult blood test (FOBT) | Stool | Traces of blood |
Fecal immunochemical test (FIT) | Stool | Traces of protein from blood |
H. pylori test | Stool, breath, or biopsy | Presence of a bacteria that can cause ulcers and gastrointestinal bleeding |
Anemia can also occur alongside lowered platelets, which are the blood cells that help form blood clots and stop bleeding. Several tests can help measure blood coagulation:
TESTS RELATED TO BLOOD COAGULATION | ||
---|---|---|
Test Name | Test Sample | What It Measures |
Partial thromboplastin time | Blood | Proteins involved in forming of blood clots |
Thrombin time (TT) | Blood | Time required for typical processes of blood clot formation |
Prothrombin time and international normalized ratio (PT/INR) | Blood | Proteins that influence blood clotting |
Iron is necessary to create red blood cells, and a decreased amount of iron is the most common cause of anemia. Multiple tests can be employed to detect iron deficiency:
TESTS RELATED TO IRON DEFICIENCY | ||
---|---|---|
Test Name | Test Sample | What It Measures |
Serum iron | Blood | Iron levels |
Ferritin | Blood | A protein that reflects the amount of iron stored in cells |
Transferrin and total iron-binding capacity (TIBC) | Blood | Proteins that bind to and help carry iron in the blood |
Soluble transferrin receptor (sTfR) | Blood | Proteins that often correlate with iron levels in the blood |
Your body needs certain vitamins to create red blood cells. Tests for nutritional deficiency may be ordered if your doctor considers this to be a possible cause of anemia in your case:
TESTS RELATED TO NUTRIENT DEFICIENCY | ||
---|---|---|
Test Name | Test Sample | What It Measures |
Vitamin B12 and folic acid testing | Blood | Levels of vitamin B12 and folate (vitamin B9) |
Methylmalonic acid (MMA) | Blood or urine | Levels of an acid that can reflect B12 deficiency |
Homocysteine | Blood or urine | Levels of an amino acid that can reflect early signs of vitamin deficiency |
Intrinsic factor antibody | Blood | A specific protein that can affect the body’s ability to absorb vitamin B12 |
Parietal cell antibody | Blood | A specific protein that can affect the body’s ability to absorb vitamin B12 |
Other medical conditions can trigger anemia. Tests may be used in order to check for underlying illnesses that negatively affect major organs and other bodily systems:
TESTS RELATED TO BODILY HEALTH AND ORGAN FUNCTION | ||
---|---|---|
Test Name | Test Sample | What It Measures |
Comprehensive metabolic panel (CMP) | Blood | 14 different elements related to metabolism, kidney function, and liver function |
Liver panel | Blood | Various proteins, enzymes, and other indicators of liver health |
Kidney (renal) panel | Blood | Electrolytes, minerals, proteins, and other compounds that reflect kidney health |
C-Reactive protein (CRP) | Blood | A protein related to inflammation in the body |
Heavy metal testing | Blood or urine | Levels of potentially toxic heavy metals including lead, mercury, and arsenic that can affect the bone marrow |
Abdominal sonogram | N/A | Provides ultrasound imaging of the abdominal organs |
Some types of infections disrupt the body’s ability to maintain a healthy number of red blood cells. Your doctor may test for signs of one of these infections if this is believed to be a potential cause of your low red blood cell count:
TESTS RELATED TO POTENTIAL INFECTIONS | ||
---|---|---|
Test Name | Test Sample | What It Measures |
HIV | Blood or saliva | Antigens or antibodies related to infection with HIV |
Epstein-Barr Virus (EBV) | Blood | Antibodies to EBV |
Cytomegalovirus (CMV) | Blood, sputum, or other fluid | Antibodies to CMV |
Getting Tested for Anemia
Anemia testing usually takes place in a doctor’s office, laboratory, or hospital. Most tests for anemia involve a blood sample that is drawn from your arm using a needle or from a prick of the finger.
Anemia can be detected on routine blood work, or tests for anemia may be ordered after a person has symptoms consistent with anemia. People receiving treatment for anemia may have follow-up testing to monitor their response to treatment.
Anyone with symptoms of anemia or other concerns about this condition should talk with their doctor to determine which tests would be most appropriate in their case.
At-home anemia testing
At-home test kits are available that can analyze blood levels that are relevant to anemia:
- Tests measuring hemoglobin, a protein found in red blood cells that may be deficient in anemia.
- Tests measuring levels of the protein ferritin in the blood that may indicate iron deficiency.
These kits involve obtaining a drop of blood after pricking your fingertip.
At-home testing does not diagnose anemia and is not a substitute for either medical care or testing ordered by a doctor and conducted in a controlled laboratory.
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