Specialty5 min read

Hematology

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A hematologist is a doctor who specializes in blood disorders such as anemia, bleeding and clotting disorders, and blood cancers.

According to ASH: haematologists are "highly specialised doctors" who work on "solving medical mysteries and saving lives, from leukaemia to blood clots and more". ASH covers anaemia ("the most common blood disorder"), bleeding disorders, blood cancers (leukaemia, lymphoma and myeloma), blood clots and sickle cell disease. ASH describes blood as having four components: plasma, red blood cells, white blood cells and platelets.

ASH says that blood performs roles including carrying oxygen and nutrients, forming clots to prevent excess blood loss, and carrying cells and antibodies that fight infection. It states that platelets above the normal level may cause unnecessary clotting, and that a low level may lead to widespread bleeding. According to the anaemia and sickle cell disease pages, your doctor may refer you to a "haematologist, a doctor who specialises in blood disorders". The professional references (Grade 4) are descriptive; this page does not cover treatment guidelines for conditions. The treatment category is decided with the doctor.

In one minute¹²³

What is it?: The specialty of diagnosing and treating blood disorders, including anaemia, bleeding and clotting disorders, and blood cancers.
Who is usually affected?: People with anaemia, sickle cell disease, a bleeding disorder, blood clots or a suspected blood disorder.
Acute or chronic?: Assessment and blood tests, then a treatment plan depending on the condition, and follow-up; this page does not cover the details of the pathway.
Main symptoms: Depends on the condition; this page does not cover lists of general symptoms.
Red flags?: Widespread bleeding, severe pain or symptoms of a clot may call for emergency care (a conservative general warning; ASH states that low platelets may cause widespread bleeding and that sickle cell disease may cause stroke, pain and organ damage).
Preventable?: This page does not cover prevention advice; ASH states that early diagnosis of sickle cell disease is important and its symptoms may begin at around four months of age.

What is it?

According to ASH, haematologists are "highly specialised doctors" in blood disorders, and it educates the public about "the importance of healthy blood" and common blood diseases such as anaemia, bleeding and clotting disorders, and blood cancers.

Conditions it covers

According to ASH: anaemia is "the most common blood disorder" and results from a lack of red blood cells; its types include iron-deficiency anaemia (the most common), vitamin-deficiency, haemolytic and aplastic anaemia, and sickle cell disease. ASH describes sickle cell disease as "the most common inherited blood disorder", in which the body produces abnormal haemoglobin S so that the cells become rigid and sickle-shaped, "get stuck and block blood flow", causing pain and organ damage, and it lists complications including stroke and acute chest syndrome.

Related pages on this site: anaemia, sickle cell disease, the blood and oncology. ASH states that your doctor may refer you to a haematologist for anaemia and for sickle cell disease, and counts blood cancers (leukaemia, lymphoma and myeloma) among what it covers. The sources of this page do not define the organisational relationship between haematology and oncology; so the link to oncology here is general and limited to blood cancers.

Common tests and procedures

ASH pages do not list diagnostic tests. ASH states that treatment of sickle cell disease includes medicines (hydroxyurea) and blood transfusion, that gene therapy is approved but not a cure, and that "the only proven cure" is bone marrow transplant. Treatment options are decided with the doctor.

When to see one

According to ASH your doctor may refer you to a haematologist for anaemia or sickle cell disease. This page does not cover the length of training or certification.

Referral to the specialist is usually decided by the primary care provider according to the condition (MedlinePlus). This page does not cover detailed referral criteria.

When do you need urgent help?

Call emergency services now 998

Widespread bleeding, severe pain, shortness of breath or symptoms of a clot or stroke: seek emergency care immediately. (A conservative general warning; ASH states that low platelets may cause widespread bleeding and that high platelets may cause clots, strokes and heart attacks; this page does not cover detailed lists of danger signs.)²⁴

Educational content only — no diagnosis, and no substitute for a clinician.

Common questions

Is anaemia always treated by a haematologist?

According to ASH your doctor may refer you to a haematologist; this does not mean that every anaemia needs a referral, and this page does not cover referral criteria.³

Questions for your doctor

What type of blood disorder do I have, and what is its cause?
Which tests are needed, and what do their results mean?
What are the treatment options, and their benefits and risks?
How often do I need follow-up and tests?
Which symptoms should lead me to contact you or go to the emergency department?

References

1
American Society of Hematology. Patient education: blood disorders. www.hematology.org/education/patients
Educational & historical references · Accessed 2026-10-06
2
American Society of Hematology. Blood basics. www.hematology.org/education/patients/blood-basics
Educational & historical references · Accessed 2026-10-06
3
American Society of Hematology. Anemia. www.hematology.org/education/patients/anemia
Educational & historical references · Accessed 2026-10-06
4
American Society of Hematology. Sickle cell disease. www.hematology.org/education/patients/anemia/sickle-cell-disease
Educational & historical references · Accessed 2026-10-06
5
MedlinePlus. Types of health care providers. medlineplus.gov/ency/article/001933.htm
Health agencies & guidelines · Accessed 2026-10-06

Review status: Edited content · Last updated: 2026-10-06

Change log

2026-10-06 — Page created.