For what reason? Is the person your employee? A related person that you cannot claim because of earnings limits?
If simply a gift to an individual then gifts are not deductible not matter what the reason.
Probably not (99% certain). But you haven't provided enough info.
One possibility: If your close relative cannot be your dependent because he had more than $4,300 of gross income, but otherwise would have qualified as your dependent (basically that you & other family members provided more than half his support), then you can include in your deductible medical expenses any qualifying medical expenses you paid on his/her behalf just as if he/she was your dependent