Is an arrhythmia dangerous?

Yes: Life threatening arrhythmias such as ventricular tachycardia and fibrillation can be dangerous. In general arrhythmias are not be neglected.

Many Types: There are many types of arrhythmias or irregular heart beats. The most common ones are benign and not dangerous and only a nuisance at most. However if your races and does not stop or you feel poorly - lighheaded, sick to your stomach, dizzy or pass out - this could be a very serious condition. The only way to determine what kind of arrhythmia you have is to see your doctor.