Marijuana is a dry, shredded mix of flowers, stems, seeds and leaves of the hemp plant Cannabis sativa. People usually smoke it as a cigarette or in a pipe. It is the most commonly abused illegal drug in the United States.

Abusing marijuana can result in problems with memory, learning and social behavior. Longer term it can lead to problems such as lung cancer and increased risk of infections. It can interfere with family, school, work and other activities.

Scientific studies are underway to test the safety and usefulness of cannabis compounds for treating certain medical conditions. Currently, smoking marijuana is not recommended for the treatment of any disease or condition.