Chocolate contains caffeine, and eating excessive amounts of it can cause nervousness, frequent urination, rapid heartbeat and difficulty sleeping. Pregnant and nursing women should moderate their chocolate consumption, as should individuals with high blood pressure, glaucoma or digestive disorders.
Chocolate, or cocoa, can cause allergic skin reactions and gastric upset, such as constipation, nausea, stomach rumbling, gas or general intestinal discomfort. The caffeine contained in large amounts of chocolate may also cause migraines and anxiety and slow the blood-clotting process, resulting in bleeding and bruising in people who have bleeding disorders. People with heart conditions should monitor their cocoa consumption as it can cause irregular heartbeat. Irritable bowel syndrome, diarrhea and gastroesophageal reflux are sometimes worsened by caffeine.
During pregnancy, the caffeine in chocolate may contribute to premature delivery, low birth rate and miscarriage. Nursing infants who consume caffeine through their mother’s breast milk might become irritable and have too frequent bowel movements. Individuals with osteoporosis, glaucoma and high blood pressure may experience unpleasant symptoms from the caffeine in chocolate, and anyone who is about to undergo surgery should cease consumption of all cocoa two weeks prior to surgery, as it can interfere with blood sugar control during and after surgery.