WHO defines anemia as “Anemia is a condition in which the number of RBC (or) their oxygen carrying capacity is insufficient to meet the physiological needs, which vary by age, sex, altitude, smoking and pregnancy state. Anemia is classified as mild , moderate and severe based on the level of concentration of Haemoglobin (Hb) in blood. Mild anemia accounts for about 10.0-11.9 g/dl, moderate anemia with Hb 7.0-9.8g/dl, severe with Hb less than 7.0g/dl. Usually women have lowered Haemoglobin level than Men. In India 90% of the females of reproductive age group have been reported to be anemic. The common cause being iron deficiency. The normal daily loss of iron is 1mg.A regular loss of 2ml of blood per day doubles the iron requirement. During menstruation 35ml of blood is lost.On average, an additional 20mg of iron is lost during menstruation. The main component of RBC is haemoglobin, which carries oxygen from the Lungs to the tissues. Iron is important for the formation of haemoglobin. The primary function of respiratory system is to exchange O2 and CO2.The body’s circulatory system is an essential link between the atmosphere which contains O2 and the cells of the body, which consumes O2 which is primarily done by haemoglobin of RBC.But in anemic individuals due to lack of Hb there is ineffective O2 delivery to the exercising muscles. Many times respiratory and circulatory symptoms are only noticeable following exertion. When anemia is severe, dypsnoea and awareness of vigorous heart action may be noted even at rest.Spirometry is a standard test used to measure how well your lungs are functioning. It works by measuring two key factors such as Forced vital capacity (FVC) and Forced Expiratory Volume (FEV) can be measured. The principle advantage of the flow volume loop is it can show whether airflow is appropriate for a particular lung volume