Bystolic is commonly used to treat high blood pressure in adults. It is a beta-blocker, meaning it affects blood flow through arteries and veins, according to Drugs.com. Bystolic helps slow a person's heart rate, improving the heart's efficiency, and lowering the risk for heart attack or stroke, reports Bystolic.com.
Common side effects of Bystolic include headache, fatigue, nausea, diarrhea and insomnia. More serious side effects that require immediate medical attention include shortness of breath, uneven or slow heartbeat, swelling in ankles or feet, and numbness in hands or feet, states Drugs.com. As of April 2015, Bystolic is not approved for use in individuals under 18 years old, according to the official website for Bystolic.