Questions and answers about the "Common Cold"; symptoms in the upper respiratory tract like sneezing, scratchy throat, and runny nose, but adults don't typically have fevers. Colds are usually caused by the rhinovirus (up to 40% of colds), or Coronaviruses (about 20%), but there are more than 200 viruses that can cause the common cold. Also questions about the seasonal flu, also called "regular flu", caused mostly by Type A and Type B Influenza viruses. Flu starts with similar symptoms as a cold only it hits faster and harder and usually includes fever in adults. Although the "stomach flu" is a common term, it is not a real diagnosis. The proper medical term for stomach flu is gastroenteritis (an intestinal disease, sometimes viral but also bacterial), it is often mistaken for influenza because the flu can sometimes include vomiting and diarrhea.