Make an image that represents the disease, injury, condition, or problem. This can be a poppet, or something ugly labeld with the disease. It can also be a peice of paper with alcoholism, HIV, asthma, or drug abuse written on it. Make the image something that represents the problem, something that will burn.
Burn this image with healing herbs inside a circle of white candles, invoking any healing gods or goddesses who appeal to you. If you are making this spell on behalf of someone else, place their photograph or something that envokes them inside the circle. Say:
By _________ I destroy you.
By _________ I am/ you are healed.