There is no prevention for lactose intolerance. Individuals may reduce their symptoms by avoiding foods high in lactose. Lactose may be better tolerated if it is eaten with other foods.
In most cases, there are no long-term effects from lactose intolerance. However, an infant with congenital lactase deficiency can become very dehydrated and fail to thrive.
Lactose intolerance is not contagious and poses no risk to others.