Common signs of heroin use include pinpoint pupils, heavy drowsiness or “nodding off,” slurred speech and slowed breathing while high, followed by flu-like withdrawal symptoms when the drug wears off. Other clues include needle marks or skin infections, drug paraphernalia, secrecy, money problems and pulling away from family, friends and responsibilities.
If you are worried that someone you love is using heroin, it is natural to feel scared, confused or even angry. Knowing what to look for can help you respond with care instead of guesswork. This guide covers the physical, behavioral and health-related warning signs, along with the overdose signs everyone should know.
What Is Heroin?
The CDC describes heroin as a highly addictive, illegal opioid drug made from morphine, which comes from opium poppy plants. MedlinePlus notes that it can be a white or brown powder, or a black sticky substance known as black tar heroin. People use it by injecting, smoking or snorting it.
Today’s heroin is more dangerous than ever. The CDC reports that most heroin now available in the United States is combined with illegally made fentanyl, a much stronger opioid. That means even someone who has used heroin before cannot know what they are getting.
Physical Signs of Heroin Use
Heroin slows down the brain and body. SAMHSA’s treatment guidance lists these signs of opioid intoxication:
- Pinpoint pupils (very small pupils, even in dim light)
- Heavy sedation and “head nodding,” drifting in and out of alertness
- Slurred speech
- Slowed movement
- A slow pulse, low blood pressure and low body temperature
MedlinePlus adds that right after using, a person may experience a rush of pleasure followed by warm flushing of the skin, dry mouth and a heavy feeling in the arms and legs. Severe itching, nausea and vomiting can also happen, followed by several hours of drowsiness.
Signs on the Skin and Body
People who inject heroin may show visible signs. StatPearls, a peer-reviewed clinical reference, notes that people who use heroin long-term often have track marks, skin abscesses at injection sites and ongoing soft tissue infections. You might notice someone wearing long sleeves in warm weather to hide their arms. MedlinePlus also describes collapsed veins among people who inject.
Not everyone injects. A CDC report found that smoking has become the most commonly documented route among overdose deaths, overtaking injection by late 2022. So the absence of needle marks does not rule out heroin or fentanyl use.
Signs of Heroin Withdrawal
With regular use, the body becomes dependent. When the drug wears off, withdrawal begins. A cycle of looking very sedated, then sick and restless, is one of the clearest signs of heroin use. SAMHSA’s guidance lists these signs of opioid withdrawal:
- Enlarged pupils
- Runny nose, watery eyes and yawning
- Sweating and goosebumps
- Fast pulse and trouble sleeping
- Stomach cramps, nausea, vomiting and diarrhea
- Bone and muscle pain, and anxiety
Someone in withdrawal may seem like they have a bad flu that comes and goes. Learn more in our guide to heroin withdrawal.
Behavioral Warning Signs
Behavior changes are often what family members notice first. These signs overlap with the criteria clinicians use to diagnose opioid use disorder, which StatPearls lists as including cravings, spending a lot of time getting or recovering from opioids, falling behind at work or school, giving up activities, and continuing to use despite problems. In daily life, that can look like:
- Secrecy, lying or disappearing for periods of time
- Asking to borrow money, missing money or valuables, or unexplained money problems
- Falling behind at work or school, or losing a job
- Pulling away from family and old friends, or new friends you do not know
- Losing interest in hobbies and activities
- Changes in sleep, appetite, hygiene or appearance
- Mood swings, irritability or defensiveness when asked about drug use
Any one of these can have other causes. A pattern of several signs, especially along with physical signs, is more concerning. For a broader checklist that includes prescription painkillers, see our guide to the signs of opioid addiction.
Items You Might Find
Because heroin is injected, smoked or snorted, you may find items linked to those methods, such as needles or syringes, burned spoons or bottle caps, cotton balls, lighters, small bags or balloons with powder or residue, burned foil, or cut straws. Finding these items is a strong reason to talk and to keep naloxone in the home.
Health Risks of Heroin Use
MedlinePlus and the CDC describe serious long-term health effects of heroin use:
- Damage to the liver, kidneys and lungs
- Mental health disorders
- For people who inject: HIV, hepatitis B and C, collapsed veins, and bacterial infections of the skin, blood and heart (endocarditis)
- Tolerance, dependence and opioid use disorder
The greatest risk is overdose. The CDC reports that nearly 162,000 people died from heroin overdose from 1999 to 2023.
Signs of a Heroin Overdose: Call 911
Heroin overdose can cause slow and shallow breathing, coma and death. MedlinePlus lists these overdose warning signs:
- Very small pupils
- Falling asleep or losing consciousness
- Slow, shallow breathing, or choking or gurgling sounds
- A limp body
- Pale, blue or cold skin, or purple lips and fingernails
Call 911 and give naloxone (Narcan) right away. The CDC says naloxone can restore normal breathing within 2 to 3 minutes, and more than one dose may be needed with fentanyl. Stay with the person until help arrives. See our step-by-step guide on how to use Narcan, and learn about fentanyl test strips.
What to Do If You Notice Signs of Heroin Use
- Stay calm and choose your moment. Talk when the person is not high or in withdrawal.
- Lead with care. Share what you have noticed using “I” statements. Avoid labels, threats or shaming.
- Keep naloxone at home. It is available over the counter.
- Offer a next step. Offer to help research treatment or make a call together.
- Get support for yourself. Family support groups and counseling can help you cope.
Our guide on how to talk to a loved one about going to rehab has more tips.
Frequently Asked Questions
What do eyes look like on heroin?
While someone is high on heroin, their pupils are usually very small, often called pinpoint pupils. During withdrawal, pupils tend to become enlarged.
Can someone use heroin without needle marks?
Yes. Heroin can be smoked or snorted, and CDC data show smoking is now more common than injecting among overdose deaths.
How can I tell if someone is high or overdosing?
Someone who is high may be drowsy but can usually be roused. If they will not wake up, are breathing very slowly or not at all, or have blue lips, treat it as an overdose: call 911 and give naloxone.
Get Help for Heroin Addiction in Lancaster, PA
Recognizing the signs of heroin use is a brave first step. Recovery is possible. The Ranch Pennsylvania Outpatient Services offers addiction treatment programs in Lancaster, including a partial hospitalization program (PHP) and an intensive outpatient program (IOP), with medication-assisted treatment available when clinically appropriate and family therapy to support loved ones. Learn more about heroin addiction and heroin addiction treatment in Pennsylvania, or verify your insurance online. Our admissions team is available 24/7, and calls are free and confidential.
