What does it mean if i have low mcv , mch and mchc (77, 23.9, 30.9)? all other platelet results were normal. bun is 8 (range was 6-20.).

MCV: Low MCV usually means microcytic anemia where your cells are smaller than normal. This is usually related to iron deficiency. But can also be related to sickle cell trait or thalassemia minor

Can't diagnose: It's your physician's decision whether to screen you for iron deficiency at this time. You know that you're describing red cell indices, not platelet problems. It's a mistake to look at any set of labs apart from the history and physical, and if there are other health issues, they must be understood in context.