Definition of a Hematologist

Why Your Doctor May Want You to See One

doctor looking at blood sample
Zero Creative/Cultura Exclusive/Getty Images

A hematologist is a specially trained physician who diagnoses and treats conditions and diseases related to the blood and bone marrow. By understanding what health conditions a hematologist diagnoses and treats, you can feel prepared and at ease if you are referred to one. 

How is a Hematologist Trained?

In order to become a hematologist in the United States, a person undergoes four years of medical school followed by three years of internship and residency in either pediatrics or internal medicine.

Then a person completes a two to three year fellowship before becoming an attending physician.

A hematologist works in a variety capacities, such as researchers and clinicians. Many hematologists also work as oncologists and are called hematologists oncologists. This means that they not only treat blood disorders but also cancer — both cancers of the blood, like leukemia, and solid tumors, like breast cancer. 

Why Your Doctor May Want You to See a Hematologist

There are a number of health problems that may warrant a referral from your primary care physician to a hematologist. For example, people who have problems with their blood cell counts — like their red blood cells, white blood cells, or platelets — may require the specialized knowledge and evaluation of a hematologist. Often times blood cell count problems are first detected on a basic blood test called the complete blood count, or CBC.

A common example of a blood count disorder is anemia, which is due to a low number of red blood cells or red blood cells that do not function well.

People who have clotting problems may also need to see a hematologist. For example, a person who develops a blood clot in their leg or lung may need to see a hematologist to evaluate why they developed the blood clot, what type of anticoagulant or blood thinner they need to be on, and the duration of their therapy.


In addition, people with bleeding disorders, like hemophilia, lack a certain blood factor necessary for clotting and may require the expertise of a hematologist. Furthermore, very serious disorders, like the blood cancers multiple myeloma, leukemia, and lymphoma, require the care of a hematologist. 

What Can I Expect If I Have to See a Hematologist?

Visiting with a hematologist is just like visiting your primary care physician. Your hematologist will obtain your medical history and perform a physical examination. Depending on the reason for your referral, he may need to order more blood tests or perform a more invasive procedure called a bone marrow biopsy. Your hematologist will communicate with you and your primary care physician on your plan of care. 


American Society of Hematology. For Patients. Retrieved December 26th 2015. 

DISCLAIMER: The information in this site is for educational purposes only. It should not be used as a substitute for personal care by a licensed physician. Please see your doctor for diagnosis and treatment of any concerning symptoms or medical condition.

Continue Reading