Caffeine can have withdrawal symptoms, most experience mild symptoms. Caffeine is known to also cause insomnia. Caffeine also lowers the body's calcium absorption by frequent urination. There are many sources of caffeine. Coffee can have up to 180 milligrams of caffeine according to which brand and how you prepare.
Tea is another source of caffeine is also contains a high content of caffeine.
Most soft drinks, chocolates, and some painkillers also contain caffeine. If you are pregnant it is advised to limit the intake of caffeine due to some studies have found a high content of caffeine may cause low birth weight. Children also should avoid an over excessive amount due to it may cause irritability and sleeplessness. It is advised that children be limited too not more than one caffeinated beverage per day. There are some good points for caffeine, if you have asthma it may help relieve an attack.