Analgesics are medications that relieve pain without turning off nerves, changing the ability to sense surroundings, or altering consciousness. They are sometimes called painkillers or pain relievers and are used to relieve pain and inflammation. There are two major groups of analgesics: anti-inflammatory analgesics and opioids. Anti-inflammatory drugs work by reducing inflammation (swelling) at the site of the pain, while opioids work by changing the brains perception of pain. Analgesics are available in many forms, including oral medications such as tablets, capsules, and liquids, topical creams, gels, and ointments, and suppositories. They are used to alleviate many types of pain, including postsurgical pain, acute pain, chronic painful conditions such as arthritis, cancer, or back pain, and aches and pains like menstrual cramps or muscle soreness. The most common form of analgesic is simple, non-opioid analgesics, which include acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs) such as ibuprofen, aspirin, and naproxen. Compound analgesics are medications containing a non-opioid along with an opioid, such as low-strength codeine.