Cytology is the examination of individual cells and surrounding material. These samples are usually gathered either by taking an impression smear, fine needle aspirate or skin scraping of the area in question. Once the sample is collected, it is either viewed freshly or dried and stained using a three-step staining technique. It is then examined under a microscope.

While this technique may often give accurate answers about general processes, sometimes additional testing, such as histopathology or bacterial culture and sensitivity, may be necessary before a definitive treatment regime is begun.