Iron Deficiency Profile (Thyrocare) aka FED is a test performed if the patient is iron deficient. Iron deficiency (or anemia) develops when your body can’t produce enough red blood cells, which are the primary carriers of oxygen to bodily tissue and organs. Iron deficiency causes dizziness, lethargy, light-headedness or malaise throughout the body. Some other common symptoms are brittle nails, hair loss, headache, irritability or shortness of breath. In case of pregnant babies it can delay the development of unborn babies.