Hematologists are internal medicine doctors or pediatricians who have extra training in disorders related to your blood, bone marrow, and lymphatic system. They’re specialists who may work in hospitals, blood banks, or clinics.
Hematologist vs. Hematopathologist
A hematologist is a doctor who treats patients with diseases and disorders that affect your blood, bone marrow, or lymphatic system (which carries fluids throughout the body and helps prevent infections). If your primary care doctor suspects that you may have one of these conditions, they will refer you to a hematologist.
A hematopathologist is a hematologists who practices in a lab. They’re trained in pathology, a branch of medicine that examines body tissues and blood with microscopes or tests. Instead of treating patients directly, a hematopathologist diagnoses diseases by studying blood and tissue samples under a microscope and using lab tests.
Hematologist education requirements
All hematologists have at least 9 years of medical education. It That includes 3 years of on-the-job training called residency after medical school and up to 4 years of subspecialty training. Some hematologists are generalists, while others focus on specific conditions and organs that require extra training.
To practice in the United States, all medical doctors (MDs) must pass the United States Medical Licensing Examination, while doctors of osteopathy (DOs) are required to pass the Comprehensive Osteopathic Medical Licensing Examination. In addition, each state has specific requirements that a hematologist and all other doctors must meet to obtain a license to practice medicine there.
When Should You See a Hematologist?
Your primary care doctor will determine whether you should see a hematologist. If you have a blood test that produces abnormal results, there’s a good chance your doctor will recommend that you see a hematologist for further investigation.
Conditions treated by hematologists
- Anemia, or low levels of red blood cells, which has many potential causes
- Deep vein thrombosis (blood clots)
- Leukemia, lymphoma, or multiple myeloma (cancers in your bone marrow, lymph nodes, or white blood cells)
- Hemophilia, a genetic blood clotting disorder
- Sickle cell disease, a form of anemia that is caused by misshaped, sticky red blood cells
- Thalassemia, another form of anemia, which results in red blood cells that are too small
- Thrombocytopenia, a condition caused by having too many platelets (which promote clotting) in the blood
- Polycythemia vera, which causes the body to make too many red blood cells
- Myelofibrosis, in which scar tissue forms in the bone marrow, interfering with production of blood cells
- Eosinophila, which occurs when the blood has too many white blood cells
- Hemochromatosis, caused by excess iron in the blood
- Von Willebrand disease, which interferes with normal blood clotting
What Does a Hematologist Do?
No surprise: Hematologists spend a lot of time checking your blood. But they don’t just diagnose illnesses. They also perform treatments, such as transfusing blood.
If you need to see a hematologist, these are some tests they may use to diagnose your condition:
Complete blood count. This common test helps your doctor diagnose or monitor your disease. Blood drawn from your vein or finger is checked for the levels and characteristics of all three types of blood cells, including platelets.
Prothrombin time. This test measures how long it takes for your blood to clot. That’s important because effective clotting is necessary to prevent excessive bleeding, such as if you have an accident. The results of this test are used to calculate your International Normalized Ratio (INR), a standardized measure of clotting time. If you take certain blood-thinning medications, your doctor will check your INR routinely.
Blood enzyme tests. Elevated levels of certain enzymes in the blood can indicate that you have a serious illness, so your hematologist may check their levels with one of these tests.
Blood differential test. This test measures how much of each form of white blood cell you have, which is an important indicator of how well your immune system is working.
Reticulocyte count. A reticulocyte is an immature red blood cell. The result of this test gives a hematologist valuable information about whether your bone marrow is making enough of these important blood cells.
Peripheral blood smear. The name of this test explains how it’s performed: A drop of your blood is smeared onto a glass plate, then a hematologist views it under a microscope. The purpose is to see if your blood cells look abnormal.
Bone marrow biopsy. If your doctor suspects that your body is having trouble making blood cells, they may order this test, in which a small needle is inserted into bone to remove a tissue sample. In a related test, called a bone marrow aspiration, your doctor will withdraw a sample of fluid, instead.
Some procedures that hematologists perform include:
Blood transfusion. This procedure replaces blood you’ve lost in surgery or an accident, or due to an illness.
Chemotherapy. A specialist called a hematologist-oncologist administers chemotherapy, which infuses your body with chemicals that kill fast-growing cancer cells.
Bone marrow transplant. Also called a stem cell transplant, this treatment replaces diseased stem cells from the spongy center of your bone with healthy cells from other parts of your body or from a donor.
Ablation therapy. A hematologist may use radiation or chemotherapy to remove diseased cells from bone marrow prior to a bone marrow transplant.
What to Expect During Your Hematology Appointment
You may not always come face to face with your hematologist. They often work closely with your internist, pediatrician, oncologist, or other primary doctor to interpret your test results or to monitor your condition. A lab technician who takes your blood sample usually isn’t a doctor. Blood draws take only minutes. You may wait a few days to get your test results.
If your primary care doctor refers you to a hematologist, at your first appointment they will likely begin by asking you general questions about your health and how you have been feeling lately to find out if you have symptoms that might be related to a blood disorder. You will probably have already had blood tests prior to your visit, so your hematologist will go over the results with you. If your results suggest that you may have a specific disease, your hematologist will discuss why and whether you need further testing. If your hematologist diagnoses a disease, they will recommend a treatment plan and other next steps.
If you have a long-term blood-related condition, such as hemophilia, you probably will see your hematologist regularly.
Takeaways
If you have a blood disease or related disorder, a hematologist will likely be part of your care team. A hematologist has expertise in diagnosing and treating a wide variety of conditions, so they will probably partner with other specialists to ensure that you get the best therapies. If you have a chronic blood disorder such as hemophilia or sickle cell disease, you will see your hematologist on a regular basis.
Hematologist FAQs
What is the purpose of hematology?
Hematology is the study of blood and the diseases that can affect it. Experts in hematology include hematologists, who treat blood diseases, and hemopathologists, who diagnose them.
What is a hematologist versus an oncologist?
A hematologist is a doctor who diagnoses and treats diseases that affect the blood, bone marrow (which produces blood cells), and lymphatic system. An oncologist is a doctor who diagnoses and treats cancer. Because cancer can arise in the blood, bone marrow, and lymphatic system, some hematologists are also oncologists.
Is seeing a hematologist serious?
Hematologists treat a wide variety of blood diseases and related disorders. Some of these conditions may have serious consequences, but your hematologist can recommend effective treatments.