Signs of Drug Addiction: How to Recognize Them

What are the main signs of drug addiction?

The signs are usually divided into three groups: what shows in the body and in how a person feels, what shows in behavior, and what happens to emotions and thinking. A single sign is easily explained by something else. The warning sign is a combination that doesn’t fade over time but grows stronger.

The most important criterion is not the sign itself but how persistent it is. A one-off bad mood or a sleepless night happens to everyone; a pattern that keeps recurring and getting worse is something else.

What physical signs point to drug use?

Physical signs are the easiest to notice if you know where to look: eyes, skin, weight, smell, coordination. None of them is one hundred percent proof, but together they form a picture that is hard to blame on fatigue or a cold.

• Eyes. Pupils that are unusually constricted or dilated, bloodshot eyes, a gaze that “drifts” or avoids contact.
• Skin. Pallor or a sallow complexion, bruises and needle marks on the arms that are hidden under long sleeves even in hot weather.
• Weight and appetite. Sudden weight loss or, conversely, bouts of hunger at unusual times.
• Sleep. Insomnia at night and drowsiness during the day, or the reverse — long stretches of sleep from which they are hard to wake.
• Speech and coordination. Slowed or, conversely, very fast and slurred speech, unsteadiness, impaired fine motor skills.
• Smell. An unusual chemical smell on clothes or hair, attempts to mask it with perfume.

A single sign from this list can mean anything. But if several of them appear together and last for weeks, that is a reason to seek a consultation rather than watch in silence.

How do the signs differ depending on the substance?

Different groups of substances act on the body in different ways, so the outward picture differs too: some speed a person up, others slow them down, still others distort perception. Knowing the general pattern helps avoid mistaking the symptoms for ordinary tiredness or a cold.

This table is a recognition guide, not instructions. Only a doctor can determine the exact type of substance and the severity of the condition after an examination and tests.

How does the behavior of a person who uses drugs change?

Family members often notice behavioral changes before physical ones; they just don’t connect them with drug use right away. The person becomes inconsistent and secretive where they used to be open, and the usual response to questions is irritation instead of an explanation.

• Money and belongings. Small sums, jewelry and electronics regularly go missing; explanations are vague or absent.
• Lying and secrecy. Confused answers about where the person has been; they keep their phone away from prying eyes.
• A new social circle. Old friends disappear, new acquaintances appear whom nobody knows anything about.
• Neglected responsibilities. Lateness, missed school or work, broken plans, all of which used to be out of character.
• A sharp reaction to the topic. Any mention of drugs or questions about how they feel trigger aggression or tears instead of a calm conversation.

The main difference from ordinary teenage rebellion or plain tiredness is duration and escalation. One-off secrecy means nothing; systematic secrecy that gets worse over months is a signal.

When do the signs point to an emergency?

An overdose is a life-threatening condition. It requires calling an ambulance immediately, not watching to see “whether it wears off on its own.” Watch for these signs, especially if several occur at once:

• confusion, or the person does not regain consciousness;
• very slow, shallow breathing or pauses in breathing;
• a bluish tint to the lips or nails;
• pinpoint pupils;
• seizures;
• vomiting while the person barely responds;
• body temperature that has risen or dropped sharply.

What should you do before the ambulance arrives?

1. Call 103. Say that you suspect an overdose and follow the dispatcher’s instructions. You can call the clinic’s 24/7 hotline after that.
2. If the person is unconscious but breathing, lay them on their side in the recovery position so they do not choke on vomit. Watch their breathing and do not leave them alone for a minute.
3. If you suspect an opioid overdose and naloxone is at hand (for example, obtained through a harm reduction program), it can be used following the dispatcher’s instructions. Even if the person feels better, the ambulance is still needed.
4. What not to do: do not give other medications or alcohol, and do not try to “revive” them with cold water.

When the ambulance crew arrives, tell them what the person may have taken and when, if you know. Show them any packaging or leftover substance: this will help the doctors.

How can you tell it’s already addiction and not a one-time experiment?

An experiment and addiction differ not in the number of times but in loss of control: the person keeps using even though it costs them their job, relationships or health, and cannot stop even when they want to.

Doctors rely on the criteria of the International Classification of Diseases (ICD-10, ICD-11). Under ICD-10, dependence syndrome is diagnosed if at least three of six signs have been present together during the past year:

• a strong desire or sense of compulsion to take the substance;
• difficulty controlling when to start, when to stop and how much to use;
• withdrawal appears without the substance, and the person uses again to relieve it;
• more and more is needed for the same effect;
• other interests and obligations fade into the background; a lot of time goes into getting the substance, using it and recovering from it;
• the person keeps using even though they already see the harm to their health, work or relationships.

This list is not a self-diagnosis test. If you recognize a loved one in it, that is a reason to see an addiction doctor, even if they insist they are “in control.” Only a doctor makes the diagnosis after an examination.

What should you do if the signs match?

The first step is a consultation with a specialist, not playing detective or making accusations in the heat of the moment. An examination by an addiction doctor will show whether there is an addiction and how much help is needed.

1. Write down the facts. Not “something’s wrong” but specifics: which signs, for how long, what has already happened because of it.
2. Get a consultation. You can get advice without the person present, to understand what to do next. Further care is described on the drug addiction rehabilitation page.
3. Treat the acute condition, if there is one, under a doctor’s supervision. How this is organized at the clinic is described on the inpatient detox page. How this stage works is explained in the article “Drug Detox: Stages and What to Expect”.
4. Move on to long-term treatment. The medical part deals with the acute phase in days, while the addiction itself requires long-term work: more on the drug addiction rehabilitation page.

What to avoid: accusations and ultimatums while the person is under the influence, secret testing “to catch them,” searching their room without talking first. This rarely changes behavior but destroys the trust without which the person will not seek help on their own.

If your loved one flatly denies the problem, start with a conversation with a psychologist: about your own boundaries and how to keep talking. More in the section on rehabilitation and support for families.

Frequently asked questions

Can drug addiction be identified by appearance alone?

No. Outward signs are a reason to pay attention, not a diagnosis. Only a doctor’s examination and, if needed, lab tests can confirm or rule out drug use.

Can I consult a doctor without giving the person’s name?

Yes. Relatives can describe the situation over the phone without giving a surname. How anonymity works when seeking help and what it means legally is explained in the article “Anonymous Addiction Treatment: What It Really Means”.

What does the cost of care depend on?

On what is needed right now: a consultation, inpatient treatment of the acute phase, or a rehabilitation program. These are different services at different prices, and the scope is determined after a consultation. Approximate prices are on the “Prices” page.

Can a person be sent to treatment without their consent?

No. An adult with full legal capacity is treated voluntarily; exceptions are rare and decided by a court. But consent rarely appears on its own: people most often come to it through a prepared conversation involving a psychologist.

How long does treatment for drug addiction take?

Treating the acute phase takes from a few days to two weeks. The addiction itself — changing behavior and thinking — needs a longer rehabilitation program and support afterward. The length of the program is chosen at the consultation, based on the person’s condition.

What should I do if a drug test is positive but the person denies everything?

Don’t start an emotional confrontation or demand an immediate confession. The test result is a reason to consult an addiction doctor. The specialist will help determine the next steps and, if needed, prepare for a conversation with the person.

This article is for information only and does not replace a consultation with a doctor. Only a specialist makes the diagnosis after an examination. If there are signs of an overdose, call 103 immediately.