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Opioids and Opioid Use Disorder (OUD)

Source: MedlinePlus Health Topics, U.S. National Library of Medicine

Last synced 8/16/2026Status: primary verified

What are opioids? Opioids, sometimes called narcotics, are a type of drug. They include strong prescription pain relievers such as oxycodone, hydrocodone, fentanyl, and tramadol. The illegal drug heroin is also an opioid. Some opioids are made from the opium plant, and others are synthetic (man-made). A health care provider may give you a prescription opioid to reduce pain after you have had a major injury or surgery. You may get them if you have severe pain from health conditions like cancer. Some providers prescribe them for chronic pain . What are the side effects and risks of opioids? Opioids can cause side effects such as drowsiness, mental fog, nausea, and constipation. They may also cause slowed breathing, which can lead to overdose deaths. If someone has signs of an overdose , call 911. These signs may include: Very small pupils of the eyes Falling asleep or loss of consciousness Slow, shallow breathing Choking or gurgling sounds Vomiting Limp body Pale, blue, or cold skin Faint heartbeat Purple lips and fingernails When using opioids, there is also a risk of opioid use disorder (OUD). What is opioid use disorder (OUD)? Opioid use disorder (OUD) means that you have a problematic pattern of using opioids. The pattern causes a lot of distress and impairment (meaning that it causes problems in and interferes with your daily life). Instead of OUD, sometimes people use the terms "opioid dependence" and "opioid addiction." Dependence means feeling withdrawal symptoms when not taking the drug. Addiction is a chronic brain disease that causes a person to compulsively seek out drugs, even though they cause harm. The risk of OUD is higher if you misuse the medicines . Misuse can include taking more than your prescribed dose or taking it more often, using it to get high, or taking someone else's opioids. Opioid use disorder and overdoses are serious public health problems in the United States. As more people misuse opioids, more women are misusing opioids during pregna

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This information is for general education and is not medical advice. Always talk to a licensed U.S. clinician about your situation, medications, or treatment decisions.