Is it difficult to have an indoor cat?

Although you are restricting the animals normal behaviour, having an indoor car is fairly easy. The only effect it would have to your health is possible allergies. Make sure you have the room! Also, make sure they have a 'multi level living space', meaning they need different levels such as book shelves, window sills, cat houses etc. Very important! Also, consider their diet. The animal will need to be on a specially formulated diet designed for animals that live indoors, I would ask your local vet. Try not to buy an overally active breeds such as Abyssinian, Burmese etc unless you have the time to give them the attention they need excersize/playing time wise. Trust me, there are a huge variety of 'personalities' in cats, I own a Burmese myself. Cats will not normally attack you while you are asleep, unless it is a kitten, then it is most likely just playing with you. If you have a problem with this then keep your door shut at night. It is best to go to your local veterinary clinic for prices of vaccinations, they vary from clinic to clinic. Also important to remember, spray/neuter your animal and always have one more litter tray than number of cats in household.