Medical marijuana is still being widely studied and researched to understand fully how it works to provide patients with relief of various symptoms caused by different medical conditions. The relief it offers will vary by condition, for example, helping patients to control their feelings of nausea, which is a common side effect of chemotherapy. In the case of people with HIV and AIDS, medical marijuana helps to boost their appetite. And in epilepsy patients, it helps to control seizures. The exact science around how medical marijuana is able to do this is still unknown, but it is believed that the chemicals in marijuana connect to the receptors in the body, which are specific parts of cells. The cannabis receptors are found in cells within the brain and immune system, but the complete process to understand how the drug affects the receptors has not yet been clearly defined or understood.