Ask for a full set of blood tests, especially ferritin, and iron levels.
It could be hereditary hemochoromatosis (iron overolad). The iron deposits land in the liver and cause enzymes to shoot up.
The good news is that if the test comes back positive, the treatment is very simple and effective, giving up about 500 ccs of blood, at first frequently, then afterwards every few months (in some countries like Canada, it can be done through regular blood donations if you otherwise qualify).
If treated early you can expect a normal, healthy lifespan. The weird thing is that it is a very common disease (1 in 200 in folks of northern European, UK or Irish stock), but not frequently picked up by doctors as the symptoms are initially so vague. As it progresses people with the disorder get varied vague complaints and are often labeled as hypochondriacs, but it is a very real and treatable condition.