Laughing is important. It's a natural way to express joy and happiness, but it can also be contagious or even the result of nervousness or stress. While there are many benefits to laughing, excessive laughter could kill you! The heart rate increases during periods of extreme laughter, which stresses the heart muscles and prevents them from relaxing. This type of laughter has been linked with sudden death in people who have a history of cardiovascular disease. So make sure that you take your time when laughing – especially if you're doing something where your heart rate might increase, for example, exercising – and don't laugh too intensely so that it doesn't put any unnecessary strain on your body!