Caffeine Summary Caffeine is a bitter substance found in coffee, tea, soft drinks, chocolate, kola nuts, and certain medicines. It has many effects on the body’s metabolism, including stimulating the central nervous system. This can make you more alert and give you a boost of energy. For most people, the amount of caffeine in two to four cups of coffee a day is not harmful. However, too much caffeine can cause problems. It can Make you jittery and shaky Make it hard to fall asleep or stay asleep Cause headaches or dizziness Make your heart beat faster or cause abnormal heart rhythms Cause dehydration Make you dependent on it so you need to take more of it. If you stop using caffeine, you could get withdrawal symptoms. Some people are more sensitive to the effects of caffeine than others. They should limit their use of caffeine. So should pregnant and nursing women. Certain drugs and supplements may interact with caffeine. If you have questions about whether caffeine is safe for you, talk with your health care provider. Food and Drug Administration Related Issues Benefits of Java Academy of Nutrition and Dietetics Caffeine and Alcohol Centers for Disease Control and Prevention Caffeine and Heart Disease American Heart Association Caffeine and Migraine American Headache Society, Committee on Headache Education Caffeine: Can It Help Me Lose Weight? Mayo Foundation for Medical Education and Research Caffeine: How Does It Affect Blood Pressure? Mayo Foundation for Medical Education and Research Energy Drinks National Center for Complementary and Integrative Health Serious Concerns Over Alcoholic Beverages with Added Caffeine Food and Drug Administration Teenagers Caffeine Nemours Foundation Children Caffeine and Your Child Nemours Foundation Caffeine Confusion Nemours Foundation Start Here Caffeine Content for Coffee, Tea, Soda and More Mayo Foundation for Medical Education and Research Caffeine: How Much Is Too Much? Mayo Foundation for Medical Education and Research Women Caffeine in Pregnancy March of Dimes Birth Defects Foundation Array Caffeine in the diet Caffeine overdose Clinical Trials ClinicalTrials.gov: Caffeine National Institutes of Health Find an Expert National Institute of Environmental Health Sciences National Institute of Environmental Health Sciences Journal Articles Caffeine Statistics and Research Update on Emergency Department Visits Involving Energy Drinks: A Continuing Public Health Concern Substance Abuse and Mental Health Services Administration Latest News Caffeine Intake — Even Dad’s — Linked to Miscarriage, Study Says HealthDay A New Health Perk for Coffee Drinkers? HealthDay
