How to Spot Substance Abuse

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People who are addicted to drugs or alcohol often need help to stop. And many people who seek treatment for drug or alcohol addiction do so because a concerned friend or family member recognized signs of substance abuse. It can be difficult to know for sure if someone is abusing drugs or alcohol, especially since some people hide their use of it. In addition, some health conditions may mirror some of the effects of drugs and alcohol, such as sleep troubles or anxiety

Read on to learn common signs of substance abuse, and how you can talk with your loved one about the possibility they have drug or alcohol problem.

Physical Signs of Drug or Alcohol Abuse

Physical changes due to drug or alcohol abuse may be immediate, or they may develop over a short period of time. Watch out for:

  • Bloodshot eyes 
  • Lack of coordination
  • Slurred speech
  • Strange-smelling breath or clothing
  • Sudden weight changes
  • Unusually large or small pupils

Behaviors That Signal a Substance Problem

Relationship troubles, health issues, work challenges, and many other things can cause changes in a person’s behavior. But when a person starts acting differently all of a sudden—and without any other explanation—it may be a result of drug use. 

Some actions that are often associated with drug or alcohol use include:

  • Being very talkative 
  • Complaining that a doctor won’t write a prescription for a certain drug 
  • Suddenly doing poorly at work or school 
  • Eating significantly more or less than normal 
  • Having excessive energy 
  • Neglecting personal care, such as wearing dirty clothes or not showering regularly 
  • Skipping important events or appointments 
  • Sleeping at odd times
  • Spending an abnormal amount of time alone 
  • Withdrawing from family and friends

Emotional Changes Due to Substance Abuse

Drugs can also affect a person’s mood and personality. People who use or abuse substances may feel especially:

  • Angry
  • Cranky 
  • Fatigued 
  • Irritable
  • Nervous
  • Unmotivated 
  • Sad 

While everyone feels these emotions from time to time, a person with a substance abuse problem may have a reaction that seems dramatic or out of character. Outbursts may seem to come out of nowhere. You might also notice extreme mood swings, where someone seems very happy one moment and very sad the next. 

Talking About Substance Abuse

Do you recognize the symptoms of substance abuse in your friend or family member? It may be time to have a talk with him or her. Try these tips:

  • Approach your loved one when he or she is sober.
  • Express your concern. You could say something like, “I’m worried about how much you’re drinking.”
  • See if your loved one would be open to visiting the doctor together.
  • Steer clear of labels like “addict” or “alcoholic.”

It can be hard to recognize symptoms of substance abuse. If you think your friend or family member has a problem with drugs or alcohol, talk with a doctor or addiction counselor about your concerns.

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Medical Reviewer: William C. Lloyd III, MD, FACS
Last Review Date: 2020 Oct 12
THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.

  1. DrugFacts: understanding drug abuse and addiction. National Institute on Drug Abuse, National Institutes of Health.

  2. Exploring treatment options for alcohol use disorders. National Institute on Alcohol Abuse and Alcoholism, National Institutes of Health.

  3. Friends and family can help. National Institute on Drug Abuse, National Institutes of Health.

  4. Mental health and substance use disorders. U.S. Department of Health and Human Services.

  5. Older adults and alcohol: You can get help. National Institute on Aging, National Institutes of Health.

  6. Prescription and illicit drug abuse: recognizing substance abuse. National Institute on Aging, National Institutes of Health.

  7. Signs of drug abuse and addiction. National Institute on Drug Abuse, National Institutes of Health.

  8. Signs of drug use. Drug Enforcement Administration.

  9. Signs of marijuana abuse and addiction. National Institute on Drug Abuse, National Institutes of Health.

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