text: blood test? co2 reading of 31  range should be 22 to 29 sgpt reading of 79 range should be 10 to 65 any info would help 31 for your co2 isn't too much over the range.  when co2 levels are higher or lower than normal, it suggests that your body is having trouble maintaining its acid-base balance or that you have upset your electrolyte balance, perhaps by losing or retaining fluid. both of these imbalances may be due to a wide range of dysfunctions. your sgpt level could be high if you have liver damage from an acute viral infection such as viral hepatitis a, b, or c, or  you have liver damage caused by medicines you have taken. other reasons could be drinking too much alcohol, mononucleosis, chronic liver infection or inflammation, gallbladder inflammation, such as may caused by gallstones, gallbladder infection, congested blood flow through the liver due to heart failure, liver cancer or another cancer that has spread to the liver, or you are taking certain medicines, such as:  medicines used to lower cholesterol levels  antifungal medicines  some narcotics and barbiturates  methotrexate  acetaminophen  salicylates (aspirin).  your doctor will probably do further testing to determine what the exact cause may be.