Deleterious Effects Of Caffeine

Caffeine is a bitter-tasting compound present in coffee, energy drinks, tea, soft drinks, chocolate and other foodstuffs. Over 90 percent of Americans consume caffeine on a daily basis, according to the National Institute of Mental Health. Although caffeine's stimulating effects can be helpful in boosting alertness, large doses of caffeine can be deleterious. If you have questions about the amount of caffeine that is right for you, consult your physician.

Tolerance and Withdrawal

A December 2009 article by researchers from Wake Forest University School of Medicine, published in the journal "Psychopharmacology (Berl.)," the stated that, as with certain other psychoactive substances, habitual use of caffeine can lead to tolerance, a situation in which progressively higher doses are needed to achieve the desired effect. Withdrawal symptoms can result when a habituated caffeine user quits. Headaches are the most common symptom of caffeine withdrawal, but other symptoms such as fatigue, irritability, problems with concentration, nausea and vomiting may also result from abrupt cessation of caffeine consumption by regular users.

Pregnancy Complications

The March of Dimes, a nonprofit focused on promoting healthy pregnancies and preventing birth defects, advises that pregnant women limit their daily caffeine intake to 200 mg, approximately the amount contained in one 12-oz. cup of coffee. Although study results have been inconsistent, some evidence suggests that excess caffeine consumption may increase the risk for miscarriage and result in lower birth weights. Additionally, infants born to mothers who consumed high amounts of caffeine in pregnancy may have faster respiration and heartbeats.

Caffeine Intoxication

Consuming more than 250 mg of coffee in one sitting has the potential to result in a caffeine overdose or "caffeine intoxication," a condition classified as a mental disorder by the American Psychiatric Association. Consuming too much caffeine usually results in no more than temporary jitteriness. However, according to the textbook "Kaplan and Sadock's Synopsis of Psychiatry," large caffeine overdoses can result in severe agitation, hallucinations, respiratory failure and even death.

Sleep Disruption

Although caffeine is prized for its ability to promote alertness and wakefulness during the day, those benefits may come at a price. According to a 2008 article in the journal "Sleep Medicine Reviews," even low daily intakes of caffeine can disrupt normal sleep patterns and lead to insomnia. Because insomnia can result in daytime sleepiness, a vicious cycle can ensue whereby a person drinks more caffeine in order to feel wakeful during the day.