A public health crisis in the United States and Canada involving a sharp increase in the use of, addiction to, and overdoses from opioid drugs, especially since 2015 (although the trend is traced to the late 1990s). Opioids, typically used as prescription painkillers, include morphine, oxycodone, hydrocodone, and fentanyl, as well as heroin, which is illegal. Ingesting high doses of opioids can cause respiratory failure and death. Also known as the "opioid crisis." The opioid epidemic has led to a staggering number of deaths in a short period of time.