American Medical Association Family Medical Guide - American Medical Association [112]
Total bilirubin
Bilirubin is an orange-yellow pigment in bile, a liquid secreted by the liver to remove waste products and break down fats during digestion. Doctors use the total bilirubin test to diagnose liver disease, jaundice (yellowing of the skin and the whites of the eyes), and obstruction of the bile duct (the tube that carries bile from the liver). The normal total bilirubin range is 0.2 to 1.1 milligrams per deciliter (mg/dL).
Direct bilirubin
The direct bilirubin test measures the blood level of a form of bilirubin called conjugated bilirubin. The blood usually contains very small amounts of conjugated bilirubin. However, damage to the liver can increase the amount of bilirubin in the blood. The normal direct bilirubin range is 0.04 to 0.20 milligram per deciliter (mg/dL).
Indirect bilirubin
An elevated level of indirect (unconjugated) bilirubin can be a sign of hemolytic anemia, pernicious anemia, or neonatal jaundice. The normal indirect bilirubin range is 0.2 to 0.7 milligram per deciliter (mg/dL).
Gamma glutamyltransferase
Gamma glutamyltransferase (GGT) is an enzyme that is usually found at high levels in the kidneys, liver, and bile ducts. Doctors use the GGT test to help diagnose disorders of the liver, bile ducts, and gallbladder, which can increase the levels of GGT in the blood. Use of some drugs such as phenobarbital and excessive intake of alcohol can increase GGT levels. The normal GGT range is 0 to 51 international units per liter (IU/L).
Lactate dehydrogenase
Lactate dehydrogenase (LDH) is an enzyme found in many tissues, especially the brain, heart, liver, kidneys, lungs, blood cells, and skeletal muscles. Doctors use the LDH test to detect tissue damage. Increased levels of LDH may be a sign of a heart attack, liver disease, lung problems, or advanced cancer. Drugs such as aspirin and some anesthetics and narcotics can also increase LDH levels. The normal LDH range is 105 to 333 international units per liter (IU/L).
Phosphorus
Phosphorus is a substance that the body uses, along with calcium, for bone development and growth. Increased levels of phosphorus in the blood can be a sign of kidney failure or hypoparathyroidism (underactive parathyroid glands). The normal serum phosphorus range is 2.4 to 4.4 milligrams per deciliter (mg/dL).
Potassium
Potassium is a mineral that is essential for maintaining nerve impulses, water balance in the body, normal heart rhythm, and muscle function. Increased levels of potassium in the blood can be a sign of kidney failure and can occur when a person is undergoing hemodialysis (a treatment for kidney failure in which a machine temporarily performs the functions of the kidneys). Decreased levels of potassium can result from fluid loss such as from excessive sweating, vomiting, or diarrhea. Medications such as angiotensin-converting enzyme (ACE) inhibitors can increase the level of potassium in the blood. Medications such as laxatives, insulin, or salicylates can decrease the amount of potassium in the blood. The normal potassium range is 3.5 to 5.3 milliequivalents per liter (mEq/L).
Sodium
Sodium is a chemical that plays an important part in maintaining the balance of water and salt in the body. Some hormones can cause a loss of sodium. Increased levels of sodium can indicate excessive loss of water (dehydration). Eating too many salty foods and not drinking enough water can also increase sodium levels. Decreased levels of sodium can be a sign of kidney disease, severe brain disease, or lung disease. Medications such as diuretics and some medications used for treating diabetes can also decrease sodium levels. The normal sodium range is 133 to 145 milliequivalents per liter (mEq/L).
Total protein
Doctors measure the level of protein in the blood to detect a variety of diseases including liver