Medical cannabis, or medical marijuana, can refer to the use of cannabis and its cannabinoids to treat disease or improve symptoms; however, there is no single agreed upon definition. The use of cannabis as a medicine has not been rigorously scientifically tested, often due to production restrictions and other governmental regulations. There is limited evidence suggesting cannabis can be used to reduce nausea and vomiting during chemotherapy, to improve appetite in people with HIV/AIDS, and to treat chronic pain and muscle spasms. Its use for other medical applications, however, is insufficient for conclusions about safety or efficacy.