Tramadol is a prescription medication used to treat moderate to moderately severe pain. It belongs to a class of drugs known as opioid analgesics and works by binding to opioid receptors in the brain, altering the perception of pain and the body's response to pain. In addition to its opioid effects, tramadol also inhibits the reuptake of serotonin and norepinephrine, which may contribute to its pain-relieving properties.