It is important to understand that anemia is not a disease by itself, but the result of a malfunction somewhere in the body. It is a quite common condition, particularly in female; estimates suggest that around one in five menstruating women and half of all pregnant women are anemic. A wide range of events, including certain diseases, specific conditions and modifications, can cause anemia. Anemia means that either the level of red blood cells or the level of haemoglobin is lower than normal. This means the red blood cells have to work harder to get oxygen around the body. Each red blood cell contains a complicated protein called haemoglobin. This protein gives red blood cell their characteristics color. It is state that when value of haemoglobin fall 5 to 6 mg/dl the person immediately gets startled and anxious then it understands that the person is anemic. Haemoglobin value is not providing sufficient information to understand the anemia because it is not a simple condition that can be merely defined by just one parameter. This article try to explain the various facets of anemia, its diagnosis, the approach, test involved, the treatment to be given and the prevention should to be taken.