Typically, wedding rings are worn on the left hand. This tradition started with the ancient Egyptians, who believed that a very delicate vein ran from the third finger on the left hand straight to the heart.
Another belief about the left hand is that a ring may be less susceptible to wear on the left. However, it is more prominent on the right hand, due to the courtesy of shaking hands. Countries such as Ukraine, Poland and Denmark traditionally place the ring on the right hand. In other countries, such as Brazil, the ring is worn on the right until the day of the wedding. After the ceremony it is switched to the left.