What Is a Hematologist Oncologist?

Medically Reviewed by Sabrina Felson, MD on December 12, 2022

A hematologist oncologist is a doctor who specializes in treating cancers of the blood. They have extra training in the blood system, lymphatic system, bone marrow, and cancers.

The term “hematologist oncologist” comes from two different types of doctors. Hematologists specialize in diagnosing and treating blood diseases. Oncologists specialize in diagnosing and treating cancers. A hematologist oncologist specializes in both. 

You might see a hematologist oncologist if you have blood cancer or suspected blood cancer. If blood cancer runs in your family, you might also see one then, too.

What Does a Hematologist Oncologist Do?

A hematologist oncologist treats cancer in patients of all ages, although some might get extra training in pediatric oncology or certain types of blood cancers. Types of blood cancers they might treat include:

Education and Training

A hematologist oncologist’s training involves many years of study. Like all doctors, hematologist oncologists first must graduate from a four-year college. Ideally, they will major in pre-med or another science. Once they’ve graduated, their education and training include:

  • Medical school
  • Residency in internal medicine
  • Fellowship in hematology oncology (3 years)

After completing a medical residency and a fellowship, they take medical exams. Only after passing those and obtaining a medical license can they start working as a licensed doctor in the field of hematology oncology.

Reasons to See a Hematologist Oncologist

If you see a hematologist oncologist, it’s likely because your primary care doctor or hematologist has recommended you see one. The primary care doctor or hematologist might suspect you have blood cancer based on your symptoms. To make sure, and to get advice on treatment, they will refer you to a hematologist oncologist.

What to Expect at the Hematologist Oncologist

When you visit a hematologist oncologist for the first time, they will review your medical history, including family history and allergies. Then they will check your vital signs — such as heart rate, blood pressure, and vision and do a physical exam. After that, they will review your test results and discuss treatment options.

Some examples of tests you might get include:

  • Blood tests
  • Bone marrow tests
  • Biopsies
  • Imaging tests

The results from these tests determine treatment options. Some treatments are:


Chemotherapy is a common treatment for cancer. It uses drugs to kill cancer cells in your body.

Side effects depend on the treatment type but can include fatigue, and hair loss. It can also lead to longer-lasting health problems once treatment stops.

Radiation Therapy

This treatment kills cancer cells by sending large bursts of energy called radiation to certain parts of your body. About half of cancer patients receive radiation therapy as part of their treatment program.

Different areas receiving radiation therapy give you different side effects. Side effects of radiation therapy vary, depending on what part of your body is getting the radiation. Some examples of side effects include dry mouth, shortness of breath, and diarrhea.

Bone Marrow Transplant

This procedure replaces damaged or diseased blood cells in your body. Replacing them restores your blood production.

Bone marrow transplants restore red blood cells, white blood cells, and platelet production. The types of bone marrow transplant that you may get are:

Autologous transplant. This transplant takes healthy blood stem cells from your own body. An advantage to this is there’s no worry about blood cell incompatibility. Before chemotherapy, your doctor will extract the blood cells and freeze them for transplant during recovery.

Allogeneic transplant. This transplant takes healthy stem blood cells from someone else’s body. The cells must be compatible with your body.

After Your Visit

After your first visit to a hematologist oncologist, you will likely continue working with that person regularly. A hematologist oncologist will work with you throughout your entire treatment program. They will be one of your lead doctors in your medical team, and can help answer any questions you might have along the way. 

Show Sources


American Medical Association: “Hematology Specialty Description.”

American Medical Association: “Medical Oncology Description.”

Guthrie: “Medical Oncology and Hematology.”

Hematology/Oncology Associates of Western New York: “Your First Visit – What To Expect.”

Leukemia and Lymphoma Society: “LAB AND IMAGING TESTS.”

Leukemia and Lymphoma Society: “TYPES OF TREATMENT.”

Mayo Clinic: “Bone marrow transplant.”

Mayo Clinic: "Bone marrow transplant: Allogeneic stem cell transplant."

Mayo Clinic: “Bone marrow transplant: Autologous stem cell transplant."

Mayo Clinic: “Chemotherapy.”

University of California, Los Angeles: “What does a hematologist-oncologist do? A day in the life of Dr. Gary Schiller.”

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