Diarrhea is a symptom -- it is not a disease. It is defined as loose, watery stools that occur more than three times in one day. The two types of diarrhea are acute diarrhea (which improves within two weeks) and chronic diarrhea (which lasts longer than two weeks). Not everyone with diarrhea needs to see a healthcare provider. You should see a healthcare provider if diarrhea is accompanied by signs of dehydration, blood in the stool, or a fever of 102 degrees Fahrenheit or higher, among other symptoms. In many cases, practicing good hygiene (washing your hands) and sanitation can help prevent the spread of diarrhea.