Opioid use disorder (OUD) is a serious medical condition. People with OUD will continue to use opioids despite negative consequences to their health, relationships, or lives.

If they try to stop using opioids, they may be unable to. They may also avoid quitting because they use opioids to function as usual. Over time, they may also build up a tolerance, increasing their risk of an overdose.

The Centers for Disease Control and Prevention (CDC) refers to opioid overdose as an epidemic. Between 1999 and 2022, almost 727,000 people died of overdoses involving opioids. Since 2013, fentanyl has played a central role in the epidemic.

Knowing the signs of an OUD can help a person seek help. Treatment works and can save a person’s life.

Learn about OUD, symptoms, treatment options, and more.

What is opioid use disorder?

OUD means that a person is psychologically and physically dependent on opioids. They cannot stop using the drugs even when they try. Additionally, they may not want to stop despite the negative consequences because they cannot function as usual without opioids.

Prescription, nonprescription, and illegal opioids can all lead to OUD. It is possible for a person to develop OUD for which a person has a valid medical prescription, especially with prolonged use.

Some examples of opioids include:

fentanyl
codeine
morphine
oxycodone
heroin

Prolonged use of opioids changes how the brain and body respond to the drugs. Eventually, a person develops a tolerance, meaning they need larger doses of the drug to get the same results they once did. Tolerance increases the risk of overdose and is also an important symptom of addiction.

Over time, the body becomes dependent on opioids. When people attempt to stop using them, they experience physical and psychological withdrawal symptoms that may cause them to return to using the drug.

Severe withdrawal without medical support can be life threatening.

Symptoms

Continuing to use opioids despite negative consequences — such as job difficulties, relationship challenges, worsening health, or financial struggles — is the hallmark of OUD.

Some other symptoms include:

being dependent on opioids to feel happy, healthy, or function as usual
experiencing withdrawal when a person attempts to quit using
prioritizing opioid use above other pursuits
breaking the law to get opioids
putting oneself or others in danger to get opioids
personality changes due to opioid use — for example, a person might become aggressive or steal from loved ones

Diagnosis

Doctors rely on symptoms to diagnose OUD.

They may also perform blood or urine screenings for opioids to assess whether a person uses opioids and is at risk for addiction.

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR), requires that a person must have at least two of the following symptoms to warrant a diagnosis:

taking opioids in larger quantities or for longer than recommended by a doctor
a desire to quit using, or unsuccessful efforts to quit
craving opioids
devoting significant time or effort to obtaining opioids
not fulfilling major obligations due to opioids
giving up important activities, such as at work or with family, because of opioids
using opioids when it is dangerous to do so, such as while driving
using opioids despite having a condition that opioids make worse
tolerance for opioids
physical or psychological withdrawal symptoms when a person stops or delays using

The International Classification of Diseases lists several subtypes of opioid addiction and dependence. The criteria for an OUD include the following:

a compulsion or strong desire to use opioids
difficulty controlling their opioid use
physiological withdrawal symptoms when a person quits or delays their use of opioids
neglecting other sources of pleasure, such as sports, hobbies, or time with families
continuing to use opioids despite negative consequences

Disorder vs. dependence

Although dependence is a hallmark of OUD, it is not the only symptom.

Dependence means a person becomes physically dependent on a chemical such as opioids. OUD or addiction means that a person also loses control over their behavior surrounding the opioid.

A person taking opioids under medical supervision might be physically dependent. However, they do not have OUD if they use only the recommended amount and do not show other signs of addiction, such as being preoccupied with opioids.

Causes

Prolonged use of opioids, especially at high doses, is the key risk factor in OUD. However, certain people may have a higher risk than others.

Researchers believe a complex interaction of biological, environmental, and psychological risk factors plays a role. They have not discovered a single gene that predicts opioid use nor determined with specificity why some people develop addictions and others do not.

Some risk factors include:

a family history of addiction
having an untreated mental health condition
living in an environment that encourages misuse
past substance misuse

Treatment and recovery

Treatment for OUD has three prongs:

addressing any issues that led to the condition, such as untreated mental health conditions or chronic pain
reducing withdrawal symptoms
managing the psychological challenges of OUD

Medication can help manage opioid withdrawal. A doctor may recommend methadone or buprenorphine to reduce symptoms.

Additionally, a person will need support. Psychotherapy, support groups, and residential treatment may help.

People who have underlying medical conditions will also need supportive medical care. This may include alternative medications for pain or treatment for conditions such as depression.

Frequently asked questions

The following section answers common questions regarding opioid misuse.

How does OUD happen?

OUD occurs when a person develops a tolerance to and a dependence on opioids and continues using them despite negative consequences. The process is gradual, but the time it takes varies from person to person.

Who is most at risk for OUD?

Anyone who uses opioids can become addicted. Those at the highest risk use opioids without medical supervision or at higher or more frequent doses than a doctor recommends.

People with a personal or family history of substance misuse and those with chronic pain or untreated mental health conditions also have a high risk.

What happens to people with OUD?

OUD can affect a person’s job, education, and relationships. It can erode their health, causing organ damage and illness. An overdose can also be fatal.

Summary

OUD is a serious medical condition where a person continues to use opioids despite negative consequences to their health and relationships. It requires medical treatment — not willpower — to cure.

People who develop OUD should contact a doctor or mental health professional for treatment and guidance.

- Dydyk, A. M., et al. (2022). Opioid use disorder. https://www.ncbi.nlm.nih.gov/books/NBK553166/

- Mitchell, C., et al. (2020). Management of dependent use of illicit opioids. https://eprints.whiterose.ac.uk/158448/1/CM_final_submitted_mitc050733.4nb.pdf

- Opioid use disorder diagnostic criteria. (2013). https://www.aoaam.org/resources/Documents/Clinical%20Tools/DSM-V%20Criteria%20for%20opioid%20use%20disorder%20.pdf

- Shah, M., et al. (2022). Opioid withdrawal syndrome. https://www.ncbi.nlm.nih.gov/books/NBK526012/

- Understanding the opioid overdose epidemic. (2024). https://www.cdc.gov/overdose-prevention/about/understanding-the-opioid-overdose-epidemic.html

- Szalavitz, M., et al. (2021). Drug dependence is not addiction—and it matters. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8583742/

- Webster, L. R., et al. (2017). Risk factors for opioid use disorder and overdose. https://journals.lww.com/anesthesia-analgesia/fulltext/2017/11000/risk_factors_for_opioid_use_disorder_and_overdose.41.aspx

This article originally appeared on Medical News Today. © 2025 Healthline Media LLC. All rights reserved. Our website services, content, and products are for informational purposes only. Healthline Media does not provide medical advice, diagnosis, or treatment.

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