Caffeine is a chemical often found in various drinks and medications. Some people consume caffeine with no visible problems, but others have a condition called caffeine intolerance. This is different from a caffeine allergy and is likely to cause discomfort rather than life-threatening reactions. Both physical and mental symptoms may persist, however, in people with this condition. Examples may include stomach upset, headache, unexplained fatigue and anxiety.
Caffeine is a naturally-occurring chemical that, when isolated in pure form, becomes a white crystalline powder. It is considered a psychostimulant widely used around the world. It occurs naturally in some chocolates, teas and coffees, and is also an added component of many energy drinks and colas, as well as diet pills and some over-the-counter pain relievers.
Caffeine intolerance occurs in some individuals who consume the chemical in any amount. With this condition, the body often lacks the enzyme necessary to digest caffeine. Those individuals therefore cannot handle the stimulation from the chemical. Rather than receive the temporary energy boosts and increased alertness that caffeine supplies to some people, caffeine intolerance may cause adverse effects on a person’s body. Such effects may take minutes or hours to become apparent.
People with caffeine sensitivity may feel immediate fatigue after consuming the chemical, while others may experience stomach upset before the fatigue ensues. This occurs as the caffeine works through the body. Ringing in the ears may be another side effect of intolerance to caffeine that stops after the body expels the caffeine.
Additional symptoms of caffeine intolerance, including headaches, insomnia, mood swings and anxiety, may be the result of caffeine dependency. Caffeine is a chemical that may become addictive because it operates with the same mechanisms as amphetamines, heroin and cocaine to stimulate the brain. The effects of caffeine are milder than those of illegal narcotics, but it manipulates the same channels in the brain. People with an intolerance to caffeine, therefore, can also be addicted to the chemical if they continue to consume it.
Unlike a caffeine allergy, intolerance does not cause anaphylactic reactions such as hives, swelling or difficulty breathing. An allergy occurs when the body mistakenly identifies caffeine and produces antibodies to attack it. The next time caffeine is consumed, histamines and other chemicals are released to combat it, causing bodily symptoms as well. This is different from intolerance, in which digesting caffeine is difficult.
People who suspect that they have caffeine intolerance may want to begin eliminating certain foods from their diet. Chocolate milk, caffeinated soft drinks, coffee, energy drinks and certain pain relievers may need to be removed from the diet. A doctor may be able to recommend approximately how much caffeine a person with caffeine intolerance can freely consume. If caffeine must be completely removed from a person's diet, there are many caffeine-free or reduced caffeine beverages and medications available.