Unintentional weight loss is a well-validated indicator of malnutrition. The significance of weight change is evaluated after the percentage of usual body weight lost in a giving period of time is calculated .Usually, weight change are more reflective of chronic,not acute,change in nutritional status.The patient weight can be unreliable or invalid due to hydration status.edema,anasarca,fluid resuscitation , heart failure,and chronic liver or renal disease can falsely inflate weight.