1 The scientific name for caffeine is 1,3,7-trimethylxanthine. 2  Caffeine is considered to be the most commonly used psychoactive drug in the world. 3  Coffee, soda, and tea are the most common sources of caffeine in the American diet.  Discontinuation of regular caffeine use may produce withdrawal symptoms.
For most patients, post concussion symptoms go away within a few days to several weeks after the original injury occurs.[In others, symptoms may remain for three to six months.In a small percentage of patients, symptoms may persist for years or may be permanent.
How long does the flu last? Flu symptoms usually persist for three to five days in people who are otherwise well. However, young children, pregnant women, the elderly, and people with chronic medical problems (like asthma, diabetes, cancer, HIV, and heart disease) may be knocked out for a longer period of time.