Hydrocodone is a prescription medication that belongs to the opioid class of drugs, sometimes referred to as narcotics. It is primarily used for the management of moderate to severe pain, as well as for certain cases of severe cough. Hydrocodone works by affecting the central nervous system (CNS), altering the way the brain and body perceive and respond to pain signals. Because of its potency and potential for misuse, hydrocodone is classified as a Schedule II controlled substance in many countries, including the United States. This means it is only legally available with a valid prescription from a licensed healthcare provider.