Haematology (or Hematology) is "The branch of medicine involving study and treatment of the blood" (Oxford Dictionaries, n.d.).
Someone who studies haematology is known as a haematologist.
It is classified into four major groups:
Coagulopathy
Anemia
Hemoglobinopathy
Hematological malignancies (Enlighten Me, n.d.)
Hemoglobinopathy
Hemoglobinopathies are "...among the most common inherited diseases around the world".
Bibliography
Enlighten Me. (n.d.). What is Hematology?. [online] Available at: https://www.superpages.com/em/hematology/ [Accessed 2 Mar. 2018].
Oxford Dictionaries. (n.d.). haematology. [online] Available at: https://en.oxforddictionaries.com/definition/haematology [Accessed 2 Mar. 2018].