What is the ruling on using hijama for purposes other than medical treatment?

Cupping (hijama) is a recommended Sunnah for whoever needs it. It is permissible, meaning recommended, when there is a need for it, and it may even become obligatory. However, if there is no need that necessitates treatment with it, then it is not recommended to perform it, as a person might be harmed by it. The Prophet, peace and blessings be upon him, performed it when he had a need for it.