Helicobacter pylori is a type of bacterium, hence it is invisible to the naked eye. However, during a gastroscopy, the gastroenterologist can infer whether a patient is infected with Helicobacter pylori by observing the mucosal appearance under the endoscope. For example, signs such as the disappearance of damages in the tiny veins, nodular changes resembling chicken skin, scattered congested spots, and others. To confirm the presence of a Helicobacter pylori infection, further tests are required. For instance, during a gastroscopy, a rapid urease test can be conducted where a tissue sample from the stomach is tested - this method is quite convenient. Alternatively, a tissue sample can be sent for pathological examination, which might take longer.