Weight gain may result from an increase in body fluid, muscle mass, or fat. Medications, fluid and salt retention, intravenous fluid infusion, kidney or heart failure are causes of increase in body fluid. An increase in body fat is commonly seen as a result of diet or lack of exercise as the body converts muscle to fat. Excessive weight gain is referred to as obesity. Obesity is a function of environmental (diet, exercise, lifestyle, etc.), hormonal, and inherited (genetic) factors in varying degrees. Obesity is associated with increased risk of illness, disability, and death. Excessive weight can result in many serious, and potentially fatal health problems, including hypertension, Type II diabetes mellitus (non-insulin dependent diabetes), increased risk for coronary disease, increased unexplained heart attack, hyperlipidemia, and infertility. However, weight gain is a normal part of pregnancy.