Poisoning is the leading cause of death in the U.S. with 9 out of 10 of those deaths caused by drugs, according to the Centers for Disease Control. In recent years, the number of drug-related deaths surpassed those of motor vehicle traffic deaths.

Recognizing signs of drug abuse may help you save one of the lives lost every year whether it’s a son, daughter, mother, father, relative or friend.

As you read the signs and symptoms, you’ll notice that many of these overlap from drug to drug. You’ll also notice that some of these signs occur normally—i.e. the poor judgment of your teenager.

Taken individually and occurring occasionally, many of these signs should not cause concern. It’s when they occur regularly enough to show a different pattern of behavior that you may want to confront your loved one.

Prescription Drugs

Many prescription drug abusers started taking a drug for medical reasons. Then they became hooked.

In 2010, about 7 million Americans took prescription drugs for non-medical reasons, according to the National Survey on Drug Use and Health (NSDUH). Pain relievers accounted for 5.1 million users while the rest were tranquilizers, stimulants, and sedatives.

The Mayo Clinic lists the following classes of prescription drugs and their abuse symptoms.

Opioid painkillers: OxyContin, Vicodin, Lortab, Darvocet, Methadone, Percocet, et al.

Common symptoms: constipation, depression, confusion, decreased respiration rate

Sedatives and tranquilizers: Xanax, Valium, and Ativan

Common symptoms: drowsiness, confusion, unsteady gait, poor judgment, involuntary rapid eye movement

Stimulants: Ritalin

Common symptoms: weight loss, agitation, irritability, insomnia, high blood pressure

In addition, here are the non-physical signs of abuse for any one of these drugs.

  • Excessive mood swings
  • Poor decision making
  • Change in appearance or routine
  • Change in eating habits
  • Neglecting personal responsibility (household chores, paying bills, patterns of taking off work or school)
  • Stealing, selling, forging prescriptions
  • Doctor shopping—finding a doctor who will write more prescriptions; having more than one doctor to write prescriptions


Meth is easy to produce, easy to obtain and powerfully addictive. Meth abusers are also relatively easy to spot because of their insidious effects on the individual.

Common symptoms and signs: loss of appetite, extreme weight loss, excited, talkative, nervousness, shaking, paranoia, depression, social dysfunction (loss of job, family, friends, or money) hallucinations, mood changes including violence, confusion

Poor hygiene is perhaps one of the biggest signs in a meth addict. This includes a pale and unhealthy complexion as well as body sores from picking at “crack bugs”—the hallucinatory skin crawling effects of meth. “Meth mouth”—broken teeth and gum infections—is another sign.


According to the National Institute on Drug Abuse (NIDA), cocaine abuse can lead “medical complications” such as heart attacks, strokes, seizures, headaches, and coma.

Common signs: talkative, mentally alert, dilated pupils, irritability, panic, paranoia, muscle spasms, excessive talking followed by periods of withdrawal and depression; weight loss, dry mouth and nose.

Regular use can lead to nosebleeds, trouble swallowing, hoarseness, and a chronically inflamed and runny nose.


Heroin is highly addictive both physically and psychologically. According to NIDA, “23 percent of individuals who use heroin become dependent on it.” Heroin is most often injected intravenously and is sometime smoked.

Common signs: Collapsed veins, abscesses, pneumonia.

If your loved one is addicted to heroin, the signs you’ll likely notice the most are their changes in behavior, which can include mood swings, neglecting responsibilities (work, school, bills, kids, etc.), stealing, and lying among others.


This green plant is the most widely used and abused drug in the country. It’s easy to obtain and in some states, can be purchased legally with a prescription.

Common signs: increased appetite, euphoric, relaxed, even lethargic, insomnia, sometimes feelings of paranoia, decreased coordination, decreased interest in completing tasks, bloodshot eyes, weakening of the immune system, bronchial infections, trouble concentrating, changes in body image.

Club Drugs

The drugs in this category commonly include LSD (acid), MDMA (ecstasy), GHB, and Rohypnol (roofies). They are most often used by teenagers and young adults at dance clubs, raves, and parties because of their euphoric and hallucinogenic properties.

Common signs: anxiety, dilated pupils, hallucinations, paranoia, nausea, perspiration.

Final Thoughts

Many of the physical signs of drug abuse are similar for different drugs. Behavioral signs are also similar. Like a movie, both the physical and behavioral signs of drug abuse will tell a story. How the story ends may be up to you.

If you are fairly certain your loved one is addicted, your next step may be an intervention. To see how this works, read “How and When to Do an Intervention”.

Since we’ve just touched the surface on each drug, you may want to find out more from our “Addictions” library on the left side.