Blood diseases are probably the most common diseases in the world. Blood is formed from the spongy bone marrow present within the bones and produces three types of blood cells namely red blood cells which carry oxygen, white blood cells which fight infections and platelets which prevent bleeding. Blood diseases can involve any or all of these blood cells and can be classified into two major categories- benign and malignant blood diseases. In simple words benign diseases are all non-cancerous blood diseases and malignant diseases are blood cancers. Here we will briefly discuss about these two major categories of blood diseases. Among the benign diseases are anemias which include iron deficiency anemia, vitamin B12 deficiency anemia also called megaloblastic anemia, and disorders due to red blood cell destruction like thalassemias, sickle cell anemias, hereditary spherocytosis, immune mediated blood cell destruction and anemias precipitated by certain drugs and viruses particularly in persons with deficiency of certain proteins in the red blood cells. Deficiency of iron is one of the most common diseases worldwide and can be due to worm infestation in children, stomach ulcers and piles in middle ages or elderly people and increased menstrual blood loss in females.
Patients taking pain killers and anti-platelet drugs can develop stomach ulcers and bleeding leading to anemia, which necessitates the examination by endoscopy and colonoscopy for searching the bleeding ulcers. Vitamin B12 deficiency is seen in people on vegetarians diet but can also be seen in others who have defects in vitamin B 12 absorptions termed pernicious anemia. Thalassemia major is an inherited red blood cell defect where thalassemia minor parents can transfer the diseases to their progeny. All pregnant females should be evaluated for thalassemia minor by hemoglobin, MCV and HPLC tests, because a child born with thalassemia major requires life-long blood transfusion. Thrombocytopenia is a condition where our platelets are destroyed within the body and patients develop bleeding manifestations due to reduced platelets. Failure of bone marrow to produce blood results in a disease called aplastic anemia. It is a life threatening condition as no blood cells are formed in such patients and these patients need urgent bone marrow transplant with healthy bone marrow from donor to replace the damaged marrow. Hemophilia is an inherited bleeding disorder, and deep vein thrombosis results from clotting of blood in our blood vessels.
The malignant diseases of blood include blood cancers. The three main categories of blood cancers include leukemias, lymphomas and myelomas. Leukemias can be acute which are immediately fatal if not treated immediately, and chronic leukemias which progress slowly and are usually not fatal immediately. Now a days leukemias are one of the highly curable diseases. Refractory, relapsed or high-risk leukemias need bone marrow transplantation for cure. Lymphomas are either Hodgkin or non- Hodgkin lymphomas and are treated with chemotherapy. Leukemias and lymphomas usually present with weakness, breathlessness, fever, bleeding tendencies and enlargement of lymph nodes, spleen and liver. Bone marrow and lymph node biopsies are done for the diagnosis of these cancers. Myeloma presents with bony pains and kidney failure and needs chemotherapy followed by upfront bone marrow transplant. Complete blood count (CBC) or Hemogram is the most common initial blood test performed to identify most of the blood disease.