Opioid Use Disorder (OUD) is the official name for addiction to opioid drugs, which is a chronic brain disease. Opioids include illegal drugs like heroin, as well as prescribed pain medications like Oxycodone, hydrocodone or morphine.
OUD is more commonly referred to as opioid addiction, opiate addiction, heroin addiction, or pill addiction and falls under Substance Use Disorder.
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Opioid Use Disorder Diagnosis & Symptoms
A doctor may diagnose opioid use disorder if a person has two or more of the following symptoms:
- Taking opioids in larger amounts or for a longer period of time than intended
- Unsuccessful attempts to cut down or quit using opioids
- Spending a lot of time obtaining, using or recovering from the effects of opioids
- Craving opioids
- Failing to fulfill major work, school, or home responsibilities
- Continuing to use opioids despite causing social, work or family problems
- Giving up important activities to use opioid use
- Using opioids in situations where it is physically dangerous (like driving a car)
- Continuing to use opioids even though a diagnosed physical or psychological problem could be made worse by opioids
- Developing a tolerance to opioids (needing more and more opioids to get the same effect)
- Feeling withdrawal symptoms when not taking opioids
Healthy vs. Opioid-Addicted Brain Scans

Opioid Withdrawal Symptoms
The symptoms of opioid withdrawal vary depending on the amount and the length of time the person has been taking opioids.
The most common symptoms of opioid withdrawal include:
- Anxiety or agitation
- Muscle aches or pains
- Insomnia or fatigue
- Dizziness and headache
- Runny nose
- Abdominal cramps, nausea, vomiting or diarrhea
- Fever or sweating
- Increased heart rate
Symptoms of opioid withdrawal usually peak within the first few days and begin to improve within a week. However, some people experience symptoms for several weeks or even months known as post-acute withdrawal symptoms.
Learn more about opioid withdrawal:
Signs of Opioid Abuse (for Loved Ones)
Behavioral symptoms are often the earliest signs:
- Being on the defensive
- Blaming others
- Lack of eye contact
- Isolation and being secretive
- Changing to a new group of friends
- Unpredictability (like not showing up without notice)
- Abandonment of daily routines or important activities
- Lack of care in personal hygiene and appearance
Opioids also take a toll on the body and physical symptoms include:
- Drowsiness
- Changes in physical appearance, like weight gain or loss
- Pinpoint (constricted) pupils
- Slowed breathing
- Constipation
- Decrease or increase in sexual desire
- Needle marks on arms, hands or feet
- Decreased appetite
Psychological symptoms may have fueled the drug use in the first place or arise because of the addiction, including:
- Sudden mood swings from irritability to euphoria
- Depression
- Anxiety
- Psychosis
- Decreased motivation
The most telling signs are environmental symptoms but these can be hard to catch:
- Doctor shopping (ex: obtaining prescriptions from different doctors, claiming they lost their prescription or needing a stronger prescription)
- Drug-related legal problems
- Paraphernalia (ex: medication bottles with labels removed, burned tinfoil, bloodied cotton swabs, syringes/ needles, bent spoons or rolled up dollar bills)
The Opioid Epidemic
Opioid epidemic is a term used to describe the sharp increase in the use of prescription and non-prescription opioids in the U.S. in the 1900s. The second wave of the opioid epidemic began in 2010 and continues to be a serious public health crisis.
How many people have opioid use disorder?
There are an estimated 2.1 million people in the United States with opioid use disorder. And, opioids are involved in around 70% of all fatal drug overdoses.
Demographics of Opioid Use Disorder

Causes of Opioid Use Disorder
There is no known cause of opioid use disorder. Many factors contribute. What makes opioid addiction more likely is:
- Genetics: At least half of a person’s susceptibility to drug addiction is linked to genetic factors.
- Chronic pain: Opioids are used to stop physical pain.
- Social factors: Those in poverty, identifying as LGBTQ+ or exposed to alcohol or opioids at a young age have a statistically higher rate of addiction.
- Mental health struggles: Opioids are used to self-medicate mental pain like depression, anxiety, bipolar or trauma.
Treatment for Opioid Use Disorder
Treatment for Opioid Use Disorder usually involves a combination of medication and behavioral therapies.
The FDA approved three medications for treating opioid use disorder:
1. Naltrexone (common brand name Vivitrol)
2. Buprenorphine (common brand name Suboxone)
Therapy for OUD can be provided at inpatient rehabs, inpatient hospitals or outpatient clinics. Intensive Outpatient Program (IOP) is a common outpatient method.
To learn more about the treatment for Opioid Use Disorder, read:
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