The doctor can use the endoscope to take photos of ulcers or remove a tiny piece of tissue to view under a microscope. If an ulcer is found, the doctor will test the patient for H. pylori. H. pylori is diagnosed through blood, breath, and tissue tests. Blood tests are most common. They detect antibodies to H. pylori bacteria.
Blood is taken at the doctor's office through a finger stick.
Breath tests are mainly used after treatment to see if treatment worked, but they can be used in diagnosis, too. The test is called a urea breath test. In the doctor's office, the patient drinks a solution of urea that contains a special carbon atom. If H. pylori is present, it breaks down the urea, releasing the carbon. The blood carries the carbon to the lungs, where the patient exhales it.