Both professional and non-professional athletes take performance-enhancing drugs. They can be dietary supplements, growth hormone, anabolic steroids or designer compounds that escape detection by doping tests. These substances affect muscle strength, endurance and the ability to pump blood, oxygenate muscles and breathe. They are sometimes called roids, stacks, andro and juice. Doctors say that these drugs can cause serious side effects such as low sperm count, breast enlargement, carpal tunnel syndrome and can decrease good HDL cholesterol and put people at risk for cardiovascular disease, heart attacks and even death.