Red Bull energy drink contains caffeine, and users can experience side effects related to their level of caffeine intake. Some side effects associated with consuming energy drinks such as Red Bull include elevated heart rate, anxiety and upset stomach. Other common side effects associated with ingesting large amounts of caffeine include headache, agitation, nausea, vomiting and chest pain. Drinking Red Bull might worsen existing conditions such as sleep disorders and diarrhea.
People suffering from certain health disorders should drink Red Bull with caution, because the drink may trigger negative side effects. Evidence suggests that individuals with bipolar disorder who consume large quantities of Red Bull risk triggering an episode of mania. People who have epilepsy should avoid drinking too much Red Bull, and so should those with Irritable Bowel Syndrome. Because caffeine raises blood pressure levels, individuals with heart conditions and high blood pressure must be wary of consuming too much of this energy drink. People with glaucoma might experience uncomfortable eye pressure for up to 90 minutes after drinking a caffeinated beverage such as Red Bull.
In addition to caffeine, Red Bull contains ingredients such as taurine, inosital and niacin. Taurine is a synthetic ingredient that sometimes acts as a mild sedative. Inosital, also called "meat sugar," is a carbohydrate, and niacin is a B vitamin. There are no medical studies to determine what side effects, if any, these ingredients have on Red Bull drinkers.