CBD may be useful either as as treatment for a specific illness or in a smaller dose for maintenance of good health. Usually, CBD is taken by mouth as oil drops or a powder that dissolves in water, or made into a food to be eaten. Another form of CBD is used on the skin as the oil or a cream to rub in. CBD is popularly taken in the 'vape' method (from the word "vapor"), with the CBD is heated so it can be inhaled. This method is favoured because the effect is felt sooner than by other means. Patients who need long-lasting relief from pain or other symptoms such as nausea, may combine two methods: for example, first vape and then eat a food made with CBD.