The answer is pretty much yes you can kill someone the feeling. That is if it's using the body is natural healing process and just speeding it up. This might work for all types of healing depends how you magic works. But again assuming that you're not actually healing person so much as speeding up their body's natural healing process. Body naturally and places damage cells with new ones. For reasons that are yet unknown the body can suddenly start producing large quantities of new cells for no apparent reason this is what's commonly called cancer. If you can control the body's natural healing process you could theoretically cause cancer.

The answer is pretty much yes – you can kill someone by healing. That is if it's using the body is natural healing process and just speeding it up. This might work for all types of healing depends how you magic works. But again assuming that you're not actually healing person so much as speeding up their body's natural healing process. Body naturally and places damage cells with new ones. For reasons that are yet unknown the body can suddenly start producing large quantities of new cells for no apparent reason this is what's commonly called cancer. If you can control the body's natural healing process you could theoretically cause cancer.