Ehrig was born Andrea Mitscherlich in Dresden, Saxony, East Germany. At the 1976 Olympics in Innsbruck, as a 15-year-old, she won a silver medal in the 3000 m event, just one one-hundredth of a second ahead of Lisbeth Korsmo who won bronze. At the 1980 Olympics in Lake Placid she came fourth in the 3000 metres.
Four years later at the 1984 Olympics in Sarajevo, competing under her first married name of Schöne, she won silver in both the 1000 and the 1500 m and became Olympic champion in the 3000 metres. In 1988, at her fourth and final Olympic Games in Calgary, competing as Andrea Ehrig, she won two more silver medals in the long distances, and a bronze medal in the 1500 metres. She became European champion five times and World Champion twice, in 1983 and 1985.