Alpha-1-Antitrypsin level may be increased in normal pregnancy and in several diseases including chronic pulmonary disease; hereditary angioedema; renal, gastric, liver and pancreatic diseases; diabetes; carcinomas and rheumatoid diseases. Alpha-1-Antitrypsin may be decreased in emphysema, hepatic cirrhosis, respiratory distress syndrome of the newborn, nephrosis, malnutrition and cachexia. If a deficiency is present, aat phenotyping may be considered to confirm heterozygous versus homozygous deficiencies.