Beta blockers are a type of drugs used to combat hypertension. They function by stopping the effects which the sympathetic nervous system has on the cardiac muscles. This allows the heart to function using less oxygen and blood, thus reducing the effort it needs to exert. Since the heart can function more easily through such relief, the blood pressure falls as a result. Beta blockers help to keep a patient's heart rate within acceptable limits, eliminating the presence of unusual heart rhythms which can disrupt cardiovascular activity. Functionally, beta blockers are considered superior to another type of drug, digitalis, which is also used as anti-hypertensive medication.

Beta blockers are useful due to their stability and predictability regarding the way they can affect and control a person's blood pressure and heart rate. Digitalis, on the other hand, is not as predicatable, due to the wide array of effects it can have on a person's physiology, including but not limited to the control of blood pressure. Digitalis may even cause toxicity (especially in female patients) due to its extremely limited therapeutic range. Digitalis lowers a patient's heart rate without atrial fibrillation, and this can be fatal for individuals suffering only from hypertension.