Influenza, or flu, is a respiratory illness caused by a virus. Flu is highly contagious and is normally spread by the coughs and sneezes of an infected person. You can also catch flu by touching an in . . .
The common cold is a viral infection of your nose and throat (upper respiratory tract). It's usually harmless, although it might not feel that way. Many types of viruses can cause a common cold. Child . . .
High blood pressure, or hypertension, occurs when your blood pressure increases to unhealthy levels. Your blood pressure measurement takes into account how much blood is passing through your blood ves . . .
Nausea is an unpleasant, diffuse sensation of unease and discomfort, often perceived as an urge to vomit. While not painful, it can be a debilitating symptom if prolonged. Nausea has many causes inclu . . .
Acid reflux occurs when stomach acid flows back up into the esophagus (the tube connecting your mouth and stomach), causing a burning sensation in the chest or throat known as heartburn. When acid ref . . .
Diarrhea is loose, watery stools (bowel movements). You have diarrhea if you have loose stools three or more times in one day. Acute diarrhea is diarrhea that lasts a short time and is common. It usua . . .