Drug Addiction Signs & Symptoms

This Page was last reviewed and changed on August 19th 2022

Content Overview

The signs of drug addiction can differ from person to person and from drug to drug: understandably, someone who is addicted to strong stimulants like cocaine are likely to behave – and appear – very differently from someone who has taken a strong depressant such as heroin, or a hallucinogen like LSD.

Some signs of long-term drug abuse and, especially, of addiction tend to be the same regardless of the specific drug being abused. For instance, a drug addict is likely to become more solitary and introverted over time; they may experience financial difficulties and struggle obtaining or retaining work; they may resort to crime to fund their habits, and display significantly altered personalities as a result both of the effects of the drugs themselves and of the consequences addiction has had upon their lifestyle life prospects.

Moreover they may suffer from a variety of conditions associated with bad nutrition and a lack of regard for personal hygiene, including skin conditions, gum disease and even malnutrition.

Physical Symptoms

Obviously, as noted the physical symptoms of drug use will vary greatly from one drug – and indeed one drug user – to the next. However, some typical signs that someone is consumed drugs may include: dilated pupils; extreme sweating; clenched or jittery jaw; jittery eyes; vomiting; visible arousal; drowsiness; flushed face; coughs; puncture marks from intravenous injection, possibly accompanied by bruises; a runny or bleeding nose; shivering; incontinence; tics; and unconsciousness.

Of course, none of these should be considered conclusive evidence that someone is using drugs; they are however some signs that someone may be doing so (especially if several of these signs are manifesting together).

Behavioural Signs

Drug abuse can result in a very broad range of behaviours. As the name suggests, stimulants tend to provide users with a great deal of invigoration, and movement and volume may be significantly exaggerated: stimulant users are likely to be extremely boisterous as well as irascible; constantly moving (possibly in time to music); and may well fidget intensely when seated.

Those using depressants, on the other hand, may well demonstrate extremely slow movement and responses, a lack of focus, an apparently profound lethargy and a tendency to drift off at any time. Meanwhile hallucinogen users are likely to display extremely unusual behaviour which may to some people resemble the symptoms of madness: a fixation upon objects or people which may not actually be there in reality; engaging in conversation with absent figures; laughing maniacally at random intervals and so on.

Psychological Symptoms

Some of the more prominent psychological symptoms of drug abuse may include (but are not limited to): wildly fluctuating moods; cognitive impairment; aggression; paranoia; incoherence; increased sexualisation, even nymphomania; greatly reduced inhibitions; significantly impaired decision-making (frequently taking place alongside engaging in extremely risky behaviour); fluctuating sleep and eating patterns; delirium; incoherence; obsessive-compulsive behaviour; delusions; and depression.

It should be noted that the connections between drug abuse and mental health are well known and many symptoms of the former resemble some of those associated with mental health issues (and vice versa). Meanwhile, depression can be caused both by the direct effects of the drugs themselves, and by the impact of addiction upon an addict’s life prospects.

At very low dosages, if the person in question is not feeling the effects especially strongly, it may be practically impossible to tell that they have taken drugs at all; beyond a certain point, however (which will vary from one individual to the next: many regular drug users develop the ability to mask their consumption of drugs quite effectively) intoxication with any drug tends to become more and more visibly obvious as the effects of the drug become felt increasingly strongly.

Which Drugs Are Considered Illicit?

In the UK, especially since the law was changed in 2016 to ban what were formerly known as “legal highs” (more correctly termed new psychoactive substances, or NPSs), the overwhelming majority of substances of abuse taken recreationally are illegal. Even prescription drugs taken recreationally are illegal to possess or supply outside the confines of the prescription.

Therefore, if someone is engaging in drug use or abuse, it is almost certain that the substance in question is an illicit one (the two most notable exceptions, of course, being alcohol and nicotine – ironically two of the most deadly drugs on Earth).

Needle and Syringe Programme

Because of the huge proliferation in NPSs developed over the last couple of decades (drug producers used to be able to circumnavigate the law to some extent by making minor tweaks to existing chemical formulae thus technically creating a new drug not specifically prohibited by UK law) it’s practically impossible to give a comprehensive list of all illicit substances which are used recreationally in this country.

However, the most prominent and frequently consumed substances of abuse remain relatively well-known drugs: cannabis, heroin, cocaine (including crack), ecstasy, ketamine, LSD, amphetamine, meth and magic mushrooms all continue to be taken regularly across the country.

Signs of Specific Drug Use:


Cannabis is most often smoked, and therefore one most obvious signs of its consumption is its distinctive smell attached to a user’s clothing or hair. Cannabis smokers will often have red quite watery eyes; they may display markedly slower reaction times than normal, and may find even the most mundane objects or comments hilarious, bursting into loud and protracted fits of laughter.

Notoriously cannabis consumption also creates intense cravings for food – known as “the munchies” – and may also cause the user to display a degree of apparent cognitive impairment, and possible confusion, when they are especially intoxicated. They may also seem drowsy and/or lethargic, and may appear extremely vacant, possibly failing to respond even to being addressed directly.


Heroin users are likely to appear very drowsy and may even nod off into sleep on occasion. They may be unable to focus mentally, becoming easily distracted and losing their train of thought; similar to cannabis users they may also display apparent cognitive impairment. Those smoking heroin may have the drug’s distinctive rich smell attached to their hair and clothing.

While those injecting it are likely to display visible puncture wounds somewhere on their skin (typically on their inner arms, though it is possible to inject the drug in many brains around the body including in the ankles and groin) and long-term users will probably display serious vascular damage. Meanwhile, those addicted to the drug and suffering from withdrawal are likely to display flulike symptoms including shivering, a runny nose and clammy skin (“cold turkey”).


Cocaine users are likely to appear extremely “pumped” – i.e. full of energy and enthusiasm, possibly moving around excessively and fidgeting a great deal when supposedly sitting still. They’re likely to speak loudly and possibly excessively about themselves; they may be extremely sexualised and disinhibited, and are frequently very aggressive, sometimes out of nowhere.

Those snorting the drug are likely to display a runny nose, and regular or long-term abuse can result in frequent nosebleeds, sometimes manifesting when the user is not taking cocaine at that particular time; meanwhile those injecting it are likely to display puncture marks as described in the “Heroin” section above; while those smoking crack cocaine may have its distinctive chemical smell surrounding them.


There are many different types of depressants of the central nervous system (CNS), including (but not limited to) barbiturates and benzodiazepines; symptoms of the present use tend to be relatively similar to one another regardless of the specific drug in question. Intoxication can resemble that of alcohol, with a loss of motor control possibly resulting in falls or other types of accident.

The user may be unable to concentrate and remain focused on any given task; they may demonstrate slurred or incoherent speech, which may tell off into nothingness as they lose their train of thought; they may be extremely drowsy and can drift off into sleep almost without warning. Occasionally they may display tightly contracted pupils though this does not apply in every case.


People who have consumed hallucinogens are likely to display behaviours which may appear extremely bizarre to other people not on drugs. For instance, they may attempt to interact physically with people or objects which are not present in reality, and may attempt to engage in conversation with those people or with other figments of their imagination.

They’re likely to be frequently distracted by sights and sounds which only they can experience, prompting rapid and possibly disconcerting head movements. They may be seized by uncontrollable laughter or moments of extreme panic with no apparent cause; their fine and gross motor skills may be extremely impaired; and their ability to judge proximity and distance may be likewise restricted. Hallucinogen use tends to result in extremely dilated pupils.

Recognising Substance Misuse in a Loved One

You are much more likely to recognise behavioural changes in someone close to you than you are necessarily the physical symptoms of drug use – especially if you are not familiar yourself with the substance in question. If someone becomes increasingly volatile, for example, over time it is not necessarily, of course, a symptom of drug abuse – but if it occurs in conjunction with some of the symptoms listed above you may feel caused concern.

Moreover, you may notice the person’s peer group changing as they associate more and more with fellow drug-takers and less and less with previously cherished friends; or you may see their outlook on life change as they lose interest in things which previously motivated them a great deal (for example sport, travel, socialising et cetera).

How to Help a Drug Addict

If you know someone addicted to drugs whom you wish to help, the first and most important thing to remember is always to protect yourself and those around you.

There are various ways in which you can assist an addict. You can arrange an intervention featuring other friends and loved ones:

  • Speak with an addiction specialist
  • Demonstrate love and care
  • Remind them that they are not alone
  • Encourage them
  • Explain to them that addiction is an illness and it needs treatment

There is no shame in going to someone for that treatment rather than attempting to overcome the addiction alone. You can help them research appropriate treatment options, and work with them to make appointments and fill out paperwork if any; you can accompany them to meetings with doctors or addiction specialists.

You can give them emotional support throughout the process of seeking and receiving help, giving them your time and love and being there for them if and when they feel they are likely to relapse, showing them understanding rather than condemnation throughout their very difficult journey back to a drug-free life.

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Frequently Asked Questions

How do I know if I have a drug problem?

While this may be a cliché it is also undeniably true: if you need to ask yourself that question, the answer is probably yes. Recreational drug use on the odd occasion tends not to prompt such thoughts: if you are concerned that you have a problem is usually because you feel you are taking drugs to excess or, even more worryingly, you have tried and failed to stop taking drugs. At this point – and especially if you develop any withdrawal symptoms after not taking the drug for a day or two – you should recognise that you have a problem.

When is it time to seek help?

Simply put, the earlier you can reach out for help the better. As soon you recognise you have a problem, try and stop taking drugs: if you manage to do so by yourself, without experiencing significant withdrawal symptoms and cravings, then you are not addicted and simply need to make sure you do not resume your drug consumption (however if you are unable to resist doing so, you are addicted). If you cannot stop taking drugs then contact an addiction specialist immediately so you can get into treatment before the problem gets any worse.

How do I stage an intervention?

An intervention is an extremely risky procedure in terms of its potential to cause great rifts between the addict and their loved ones, so getting it right is essential. With this in mind if you are contemplating putting an intervention in place, it’s important that you contact an addiction specialist for advice rather than simply going it alone without any experience: things can go very wrong, with long-term implications for everyone involved.

Who is at risk of drug addiction?

Although scientists and doctors have not yet been able precisely to identify the specific causes of addiction, it’s clear that both environmental and genetic factors play roles, and as a result people with certain experiences – for example, childhood abuse or repeated trauma – are more likely than others both to engage in substance abuse and subsequently to develop addiction. However, there is no hard and fast rule, and one person may become addicted while another with exactly the same experiences may not. Effectively, anyone taking addictive substances repeatedly over any length of time is at risk of developing an addiction to them, regardless of background.

What are the common signs of substance abuse?

There are a great many different signs and symptoms of drug abuse – different drugs have different signs associated with them, while different people may react differently to drug use and abuse. Typically, drug consumption may result in the manifestation of signs and symptoms including, but not limited to: dilated pupils; impaired motor control, cognitive functions, communication skills and decision-making; mood swings; sweating; nausea; dizziness; drowsiness; lethargy; extreme exuberance; hyper-sexualisation; irritability; aggression; depression; flulike symptoms; euphoria; heightened empathy; and many more.

What are the risk factors associated with drug addiction?

There are a broad range of risk factors, both environmental and genetic, associated with drug addiction. Some of the most prominent include childhood abuse and repeated trauma; exposure to substances of abuse in the home was growing up; a peer group amongst whom drug abuse is common; poverty; early exposure to alcohol; a member of the family with a substance abuse disorder.

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