Before coming to Nepal you will need to be immunized against Typhoid, Polio, Meningitis, Hepatitus A and B.
It can take some time to have these immunizations done properly so give yourself plenty of leeway before you come to Nepal. Make sure your tetanus shots are current too.
There are still some cases of Malaria in Nepal but it is only down in the Terai ( flat lands of Nepal ). It is your personal choice whether to take malaria tablets but note that sometimes the side effects are quite strong. If you are visiting Bardia National Park or Chitwan it may be an idea to take this medication however the best prevention is to be protected against the mosquitoes, wear long sleeve clothing and use repellent that you bring from home.
It is a good idea to have a full dental check before arriving in Nepal as the dentists in Nepal may not be quite as reliable as your own.
It is important to be mindful of your hygiene and be careful what you eat. For example make sure you always eat cooked food when you are eating anything from street sellers. All our trips have the highest quality of sanitization and all the water is iodized. One of the ailments that travelers sometimes get in Nepal are dysentery either amoebic or bacterial and most of the time it is from eating something dodgy in town and is almost always contracted in Kathmandu before getting to the river.