Caffeine presents many side effects to regular users and also moderate consumers. At one point many researchers looked to link caffeine with heart disease and cancer. Also many studies have shown that blood pressure is increased with the consumption of caffeine, but the results of these studies vary. For the most part these beliefs have been put to rest due to extensive testing. Currently there is no evidence that links caffeine to cancer, cardiovascular disease, or high blood pressure. However, caffeine causes many side effects that can still cause many problems among athletes as well as the regular person. These side effects include sleep deprivation, nausea, cramping, anxiety, fatigue, headaches, and gastrointestinal instability. For athletes, caffeine has more disastrous effects that may affect performance. These side effects include muscle tightness, muscle cramping, and dehydration. The threat of any of these problems during competition is enough to make any athlete think twice before using caffeine in a major event