There are many reasons for the decrease of red blood cells and platelets, which may include myelodysplastic syndromes, megaloblastic anemia and autoimmune diseases. 1. Myelodysplastic syndrome: it can cause abnormal bone marrow hematopoietic function and induce hematopoietic failure, which in turn leads to the reduction of red blood cells and platelets. 2. Megaloblastic anemia: malnutritional anemia induced by the lack of folic acid and vitamin B12 will lead to the reduction of the peripheral blood trichomonads, which will in turn lead to the reduction of red blood cells and platelets. 3. Autoimmune diseases, etc.: For example, the common systemic lupus erythematosus will induce the appearance of systemic disease damage, leading to a decrease in the total blood cells, inducing erythrocyte and thrombocytopenia. Red blood cells and thrombocytopenia may also have other causes, it is recommended to go to the regular hospital as soon as possible to receive further examination, according to the results of the treatment.