Some blood disorders and diseases include anemia, malaria, leukemia and essential thrombocytosis, according to WebMD. Anemia and malaria affect red blood cells, and leukemia and essential thrombocytosis affect white blood cells.
Anemia means a person has a red blood cell count that is too low, claims WebMD. Often, mild anemia does not cause symptoms, but severe anemia may cause pale skin, fatigue and shortness of breath. Malaria is a blood disease that infects a person following a mosquito bite. Mosquitoes transmit the malaria parasite to a person's blood, causing chills, fever and organ damage. Malaria most often occurs in Africa, but it can occur anywhere.
Leukemia is a blood cancer that causes white blood cells to turn malignant and multiply inside the bone marrow, as stated by WebMD. Leukemia may form rapidly and severely, known as acute leukemia, or progress slowly, known as chronic leukemia. Doctors use both chemotherapy and bone marrow transplants to cure leukemia.
Essential thrombocytosis is a condition where the body begins to produce too many platelets in the blood. As of 2015, there is no known cause for essential thrombocytosis. Since platelets do not work correctly, patients with this condition may suffer from excessive bleeding, clotting or both.