Although moderate amounts of caffeine might have beneficial effects, such as improved focus and increased energy, excessive intake can be harmful. Substitute decaffeinated beverages or other drinks for caffeinated products if your caffeine intake is too high and read food and beverage labels carefully to keep track of your caffeine consumption.
Most adults can consume between 200 and 300 mg of caffeine per day without negative side effects, as noted by MayoClinic.com. This amounts to approximately two or three cups of coffee. Some people are more sensitive to caffeine than others, so you might need to limit your intake even more if this amount causes negative side effects. Men tend to be more sensitive to caffeine than women. Avoid consuming more than 500 or 600 mg of caffeine on a regular basis.
Monitor your caffeine intake in order to avoid negative side effects and health problems. On average, a 5 oz. cup of coffee contains about 115 mg of caffeine, according to the Nemours Foundation. A 12 oz. glass of iced tea, on the other hand, contains 70 mg, although the longer you brew your tea, the higher the caffeine content. Energy drinks and soda might contain anywhere from zero to more than 100 mg of caffeine, and medications like Excedrin and Vivarin contain well over 100 mg.
Habitual caffeine use might cause addiction and your body will experience withdrawal symptoms if you don't receive caffeine every 12 to 24 hours. According to the American Heart Association, the most common symptoms are headache, fatigue, restlessness and depression. If you consume too much caffeine, you might experience insomnia, irritability, restlessness, fast heartbeat and muscle tremors. Caffeine also causes the stomach to produce acid, which might result in heartburn. In extreme cases, caffeine overdose can have more serious side effects. According to the United States Federal Drug Administration, a 19-year-old man died from overdosing on caffeine pills.
Some groups should be especially careful to limit their caffeine intake. Pregnant women, for example, should limit caffeine intake to 200 mg per day, according to the American Pregnancy Association. Nursing women also should limit their caffeine intake, since it passes through breast milk. If you take any daily medications, be sure that caffeine does not interact with their effectiveness or cause unwanted side effects. If you have trouble sleeping, avoid drinking caffeinated beverages close to bedtime, which might aggravate the problem.