Diarrhea, food poisoning, High altitude sickness are the familiar problems for clients in the Mountain area. Hepatitis A is one of those not so bad but ordinary disease in Nepal. It won't kill you, but it'll put a speedy end to your travels, and it may place you up for several months after your return. It's transmitted through tainted food and water. There are some diseases like Malaria, Typhoid, meningitis, Japanese B encephalitis and rabies all fall into the potentially fatal but rare category.