Tachycardia is a condition where the heart beats much faster than normal. The rate at which the heart beats can vary a little but when it is too fast or too slow, it can be cause of concern. When the heart beats too fast, it pumps less efficiently and supplies the rest of the body including the heart with less blood flow. This can lead to a heart attack. Mental conditions like anxiety or change in environment can cause tachycardia. This could also be due to conditions of the heart, kidney, bowels, respiratory or neuromuscular.