What is an anoscopy? An anoscopy is a procedure that uses a small tube called an anoscope to view the lining of your anus and rectum. A related procedure called high resolution anoscopy uses a special magnifying device called a colposcope along with an anoscope to view these areas. The anus is the opening of […]

What is an anion gap blood test? An anion gap blood test is a way to check the levels of acid in your blood. The test is based on the results of another blood test called an electrolyte panel. Electrolytes are electrically charged minerals that help control the balance of chemicals in your body called acids and bases. Some

What is an ANA (antinuclear antibody) test? An ANA test looks for antinuclear antibodies in your blood. If the test finds antinuclear antibodies in your blood, it may mean you have an autoimmune disorder. An autoimmune disorder causes your immune system to attack your own cells, tissues, and/or organs by mistake. These disorders can cause serious

What is an amylase test? An amylase test measures the amount of amylase in your blood or urine. Amylase is an enzyme, or special protein, that helps you digest food. Most of your amylase is made in the pancreas and salivary glands. A small amount of amylase in your blood and urine is normal. A

What is amniocentesis? Amniocentesis is a test for pregnant women that looks at a sample of amniotic fluid. Amniotic fluid is a pale, yellow liquid that surrounds and protects an unborn baby throughout pregnancy. The fluid contains cells that provide important information about your unborn baby’s health. The information may include whether your baby has a certain birth defect or genetic

What is an ammonia levels test? This test measures the level of ammonia in your blood. Ammonia, also known as NH3, is a waste product made by your body during the digestion of protein. Normally, ammonia is processed in the liver, where it is changed into another waste product called urea. Urea is passed through

What is an ALT blood test? ALT, which stands for alanine transaminase, is an enzyme found mostly in the liver. When liver cells are damaged, they release ALT into the bloodstream. An ALT test measures the amount of ALT in the blood. High levels of ALT in the blood can indicate a liver problem, even

What is an alpha-fetoprotein (AFP) test? Alpha-fetoprotein (AFP) is a protein produced in the liver of a developing fetus. During a baby’s development, some AFP passes through the placenta and into the mother’s blood. An AFP test measures the level of AFP in pregnant women during the second trimester of pregnancy. Too much or too little

What is an AFP (alpha-fetoprotein) tumor marker test? AFP stands for alpha-fetoprotein. It is a protein made in the liver of a developing baby. AFP levels are usually high when a baby is born, but fall to very low levels by the age of 1. Healthy adults should have very low levels of AFP. An