Lactose intolerance is the inability to digest significant amounts of lactose (the major sugar found in milk). Symptoms of this condition include nausea, cramps, and abdominal pain, among others. In order to make a lactose intolerance diagnosis, your healthcare provider will ask questions about your symptoms, perform a physical exam, and recommend certain tests. While lactose intolerance tests can be used to make the diagnosis, your healthcare provider may first recommend eliminating cow's milk from the diet to see if the symptoms go away.