We have very little information at all about Viking medical practices. It is thought that women were probably the primary medical practicioners (Foote and Wilson, The Viking Achievement, p. 93). Since women in general are so much in the background in most sagas, you don't see them operating in this role often, and even male physicians don't get much description when they appear. In particular, after Christianity began to appear, men in all European contexts tend to hold the official titles associated with medical roles, although women remained very active as the first line of everyday healthcare in their homes (Ellis-Davidson, Roles of the Northern Goddess, p. 161).