Abnormality of blood and blood-forming tissues

What it means

An abnormality of the hematopoietic system.

The hematopoietic system comprises the organs that are involved in the production of blood, primarily the bone marrow, spleen, tonsils, and lymph nodes.

In everyday care

Most people with this sign do not have a rare disease — it appears in common conditions far more often. These general reference pages cover the same topic:

Rare diseases that can present with this19

The range is how often this sign appears among people diagnosed with each disease — it is not a probability of having any of them. Many of these signs also occur in common, non-rare conditions. A sign on this page is a conversation to have with a clinician, not a conclusion.

Part of the broader category

Also called: Abnormality of the haematopoietic system · Abnormality of the hematopoietic system · Haematological abnormality · Hematologic disease · Hematological abnormality