This test looks for white blood cells in your stool. This can help your healthcare provider figure out what's causing inflammatory diarrhea.

This test looks for bacteria, viruses, and other organisms in your stool. This test can help find out what's causing a digestive tract infection.

This test finds out what's causing your lung infection. Sputum, or phlegm, is the mucus that settles in the lower airways of your lungs when you have an infection or a chronic illness.

This test measures the amount of sodium, or salt, in your urine. This test can help your doctor find out whether you have too much salt in your diet.

This test measures how much sodium you have in your blood. Too much or too little can lead to health problems like high blood pressure.

This test measures the level of a substance called rheumatoid factor in your blood. It helps your doctor find out whether you have rheumatoid arthritis.

Rh typing is very important during pregnancy. If you are Rh negative and your baby is Rh positive, you may have an Rh incompatibility.

This test measures the number of reticulocytes in your blood. It can be used to diagnose anemia and find out why you have a disease.

A red blood cell (RBC) count is a blood test that measures the number of red blood cells, or erythrocytes, in your bloodstream.

This test looks for antibodies to red blood cells (RBCs) in your blood. These antibodies can cause problems during blood transfusions or, if you're pregnant, with your unborn baby.