Skip to Content

Drug signs and teenagers

It's common for parents to worry that their teenagers will use drugs. Learn the signs of drug use so that you can be alert. Early intervention on your part can help your teen stay out of trouble from drugs.


Learn about the different types of drugs that may be used.

Older teens are more likely to use drugs than younger teens. Marijuana (pot) is still common. More and more teens are using prescription drugs.

  • About 1 out of 7 high school seniors have used prescription drugs.
  • About 1 out of 3 have used marijuana in the last year.
  • Younger teens use drugs that are inhaled more than older teens.

Keep your eyes open for signs of drug use. Physical signs include:

  • Slow or slurred speech (from using downers and depressants)
  • Rapid, explosive speech (from using uppers)
  • Bloodshot eyes
  • Cough that does not go away
  • Unusual odor on breath (from using inhalant drugs)
  • Pupils are extremely big (dilated) or extremely small (pinpoint)
  • Rapid eye motion (nystagmus) -- a possible sign of PCP use
  • Loss of appetite (occurs with amphetamine, methamphetamine, or cocaine use)
  • Increased appetite (with marijuana use)
  • Unsteady gait

There may be noticeable changes in your teen's energy level. You may notice:

  • Sluggishness, listlessness, or constant sleeping (from using opiate drugs, such as heroin or codeine, or when coming down off stimulant drugs)
  • Hyperactivity (as seen with uppers such as cocaine and methamphetamine)

Your teen's behavior may change. You may notice:

  • Poor grades in school and missing more school days
  • Not taking part in usual activities
  • Change in group of friends
  • Secretive activities
  • Lying or stealing

Get help early for your teen. Help them stop using drugs before it becomes a more serious problem.

More information is available at


Stager MM. Substance abuse. In: Kliegman RM, Stanton BF, St. GemeIII JW, Schor NF, Behrman RE, eds. Nelson Textbook of Pediatrics. 19th ed. Philadelphia, PA: Elsevier Saunders; 2011:chap 108.

National Institute on Drug Abuse: Preventing drug use among children and adolescents. NIH Publication No. 04-4212(B). 1997. Revised October 2003. Accessed August 8, 2013.

Related Images

Review Date: 8/18/2013
Reviewed By: Linda J. Vorvick, MD, Medical Director and Director of Didactic Curriculum, MEDEX Northwest Division of Physician Assistant Studies, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.
The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2015 A.D.A.M., Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

Learn more about Drug signs and teenagers