Learn about the risks and general concerns of drug abuse and the chemistry between the brain and addiction.

Using drugs might seem harmless, especially if you know people who use drugs and don’t appear to suffer any consequences. The truth is that drug use can present a wide range of risks and dangers, and staying informed can be an important first step to staying safe.

The Substance Abuse and Mental Health Services Administration (SAMHSA) reports that in 2013, 24.6 million (or 9.4 percent) people aged 12 or older in the United States had used illegal drugs in the past month. Of them, SAMHSA found, 6.9 million were drug-dependent or abusing drugs. They also found:

  • Marijuana is the most popular illicit drug, following by nonmedical use of prescription pharmaceuticals such as opiate painkillers.
  • People aged 16-34 were more likely to use drugs (over 10 percent of Americans aged 12 and up), with people 18-25 using drugs at the highest rates (over 20 percent of Americans aged 12 and up).
  • Over 22 percent of full-time college students aged 18-22 use illegal drugs (26 percent of males and 19 percent of females).
  • Rates of drug use are lower among people who are college graduates (about 7 percent) compared to people who have not graduated from college (10-12 percent).
  • About 9 percent of people who are employed use illegal drugs compared to 18 percent of people who are unemployed.
  • Drug use is most prevalent in the western United States and least prevalent in the southern United States.

Misuse of drugs and alcohol caused nearly 2.5 million emergency room visits in 2011, SAMHSA reports. The Centers for Disease Control and Prevention (CDC) found that 43,982 people died of drug overdose in 2013, and the CDC also found that over double that number – about 88,000 – die from excessive alcohol consumption each year.

Overdose isn’t the only risk associated with drug use – drugs can also impact your physical, psychological, and behavioral health in a wide variety of ways.

Risks of drug use

Although the risk of addiction exists for any drug user, most people who use drugs successfully avoid becoming addicted. However, this doesn’t mean that they aren’t taking other risks when trying drugs.

The method of use may carry a range of inherent health risks:


Drinking alcohol greatly increases the risk of developing cancers of the digestive tract.


Edible marijuana may come in much higher doses than inexperienced or casual users are accustomed to, resulting in emergency room visits related to excessive use. Edible marijuana also often takes the form of candies, chocolates, pastries, or other foods that are desirable to children. A study in Jama Pediatrics found that Colorado’s decriminalization of medical marijuana resulted in a spike of children admitted to emergency departments. The Denver Post reports that the subsequent legalization of marijuana in Colorado caused the rate of children admitted to the Children’s Hospital Colorado for accidentally eating marijuana to roughly double from decriminalization levels.


Snorting drugs like cocaine, methamphetamine, or heroin can cause irritation and inflammation of the soft tissues of the nose, especially if impurities are present in the drug. This can cause tissue damage and can even result in the nasal septum (the wall between the two sides of the nose) becoming perforated. Other effects include:

  • Nosebleeds
  • Chronically runny nose
  • Loss of sense of smell
  • Problems with swallowing


Smoking marijuana exposes the user to carbon monoxide, tar, and ash. Over time, these accumulate in the lungs and can cause:

  • Regular coughing
  • Increased phlegm or mucous
  • Wheezing
  • Chest sounds in the absence of a cold
  • Chronic bronchitis
  • Decreased activity of lung immune cells

Smoking tobacco opens the user to all these risks, as well as the risk of cancer.


Injecting drugs like heroin, cocaine, or methamphetamine opens up the user to a number of dangers, including:

  • Boils
  • Scarred or collapsed veins
  • Cell death
  • Arthritis
  • Soft tissue infections
  • Infections of the heart valves or blood vessels
  • Blood-transmitted infections such as HIV or hepatitis (if sharing needles)
  • Organ damage

Many drugs loosen inhibitions, impair judgment, or impair coordination and reflexes. This can cause:

  • Engaging in unsafe sexual behavior, such as having sex with strangers or unprotected sex
  • Increased risk of injuries from accidents, such as falls or burns
  • Increased risk of experiencing violence

Overdose can manifest in a variety of ways depending on the type of drug used:

  • Stimulants (such as cocaine, methamphetamine, ecstasy, or bath salts) can overexcite the brain, causing seizures, or the cardiovascular system, causing heart attack or stroke.
  • Depressants (such as alcohol, opiates, or benzodiazepines) can lower the body’s breathing levels to the point where breathing stops, or slow the heart until it stops. They can also directly cause unconsciousness, coma, and death.
  • Some drugs (such as alcohol and opiates) can cause both vomiting and unconsciousness, which can be a lethal combination. If someone vomits while unconscious, they can choke on the vomit and suffocate. If you encounter someone who you suspect has overdosed on drugs, roll them onto their side to reduce the risk of this happening while you call emergency services.

General health concerns of drug abuse

Physical concerns

  • Dependence or withdrawal symptoms (when attempting to quit)
  • Weakened immune system
  • Lung, liver, or cardiovascular disease
  • Cancer
  • Malnourishment

Psychological concerns

  • Anxiety
  • Depression
  • Insomnia
  • Forgetfulness or memory loss
  • Difficulty concentrating or paying attention
  • Cravings and addiction

Behavioral concerns

  • Losing interest in family or friends in favor of new, drug-using friends
  • Losing interest in activities or hobbies previously enjoyed
  • Being late to or skipping work or school
  • Poor performance at work or school
  • Deceitful or dishonest behavior, such as lying about drug use or stealing money to buy drugs
  • Neglect of personal hygiene

Addiction and the brain

Drugs can work in one of two ways: by mimicking the effects of one of the brain’s own signaling chemicals, or by causing nerve cells in the brain to release extra signaling chemicals. Either way, the receptors for these chemicals get flooded with signals. In the case of chemicals that signal pleasurable feelings – such as dopamine, serotonin, endorphin, or endocannabinoid – this flood produces a euphoric rush or high.

To defend themselves against this onslaught, the brain’s nerve cells will reduce the number of receptors they have for the signaling chemicals, quieting the incoming signal. This means that, without the drugs, levels of the signal become too low for the brain to function properly. The result can be a crash, hangover, or, when the user has become dependent on the drug in order to function, full-blown withdrawal symptoms. Over time, the rewarding effects of the drug become lower, and eventually, the user winds up using drugs simply in order to stave off the effects of withdrawal rather than for the high they once felt.

A review of research in the Proceedings of the National Academy of Sciences found that people who are addicted to drugs show a substantially reduced dopamine response to drug use. However, they have an increased dopamine response in the reward pathway when exposed to cues associated with drugs, which in turn predicts the strength of drug cravings. They also have lower levels of dopamine receptors in the orbitofrontal cortex and anterior cingulate gyrus, which are associated with self-control and inhibition.

Concerns of drug use, abuse, and addiction by drug


Alcohol can be safe to consume in moderation, but heavy drinking over time can cause:

  • Liver disease
  • Inflammation of the pancreas
  • Cardiovascular problems, such as high blood pressure and stroke
  • Damage to the brain, particularly areas related to movement, mood, thinking, and judgment

Alcohol also remains, by far, the most common date-rape drug. Brown University reports that 90 percent of all campus rapes occur when the assailant or the victim has used alcohol.


Barbiturates such as phenobarbital, if used in the long-term, can cause:

  • Irritability
  • Memory loss
  • Changes in alertness
  • Loss of functioning

Bath salts

Bath salts (cathinones) include mephedrone, methylone, and MDPV, as well as many others. They may be sold as ecstasy (MDMA or “Molly”) due to their chemical similarities to the drug. Their use can cause:

  • Cardiovascular problems
    • Racing heart beat
    • High blood pressure
    • Chest pain
  • Paranoia and panic attacks
  • Kidney failure

The long-term effects of bath salts are not yet fully understood, but NIDA reports that their addictive potential may be as high as methamphetamine’s.


Benzodiazepines include Xanax, Ativan, Klonopin, and Valium. Long-term use of benzodiazepines can cause:

  • Memory problems
  • Clouded thinking
  • Mood swings
  • Sleep problems
  • Irritability or aggression
  • Headaches
  • Dizziness
  • Lethargy


Cocaine poses risks when used in a binge pattern, and its abuse may lead to:

  • Restlessness
  • Irritability
  • Agitation
  • Anxiety
  • Insomnia
  • Mood disturbances

Heavy cocaine users are at risk for experiencing acute, severe paranoia, losing touch with reality, and falling into a temporary state of psychosis.

Cough Medicine

Cough medicine (DXM) is safe to use as directed, but in high doses can cause:

  • Impaired coordination
  • Numbness
  • Nausea or vomiting
  • Raised blood pressure and heart rate
  • Agitation
  • Raised body temperature
  • Building of acid in body fluids

Cough medicines may also be dangerous to use in high doses because of their other ingredients, such as:

  • Pseudoephedrine, which increases blood pressure
  • Acetaminophen, which can cause liver damage
  • Antihistamines, which can damage the brain and heart


Ecstasy (MDMA) abuse can cause:

  • Irritability
  • Anxiety
  • Impulsiveness
  • Sleep disturbances


GHB abuse can cause:

  • Depression
  • Mood swings
  • Damage to memory, judgment, and decision-making abilities
  • Vision problems
  • Slurred speech

Since GHB is odorless and tasteless and can produce inhibition and unconsciousness, it can be used as a date-rape drug.


Heroin and prescription opiates slow the heart and breathing. They include codeine, morphine, Vicodin (hydrocodone), Percocet/OxyContin (oxycodone), Dilaudid (hydromorphone), and Demerol (meperidine). Although prescription opiates are safe to use as a doctor prescribes, using them in higher doses or more frequently can be dangerous, risking coma or death.


  • Hydrocarbon Inhalants include solvents, glues, gases, and aerosols. Their use can cause:
    • Nerve damage
    • Tremors
    • Permanent movement problems
    • Liver or kidney damage
  • Amyl nitrites can cause lipoid pneumonia, a form of lung inflammation caused by the drugs entering the lungs.
  • Nitrous oxide inactivates vitamin B12 in the body, a nutrient necessary for maintaining the nervous system. Long-term B12 depletion can cause nerve damage.


K2/Spice, also known as “fake weed,” is sold as a legal alternative to marijuana. However, it can contain a wide range of cannabinoid-like compounds with unreliable effects. Acute problems from spice use can include:

  • Nausea and vomiting
  • Agitation and confusion
  • Hallucinations
  • Elevated heart rate
  • Reduced blood supply to the heart
  • Heart attacks

The long-term effects of spice are not yet known.


Ketamine abuse over time can cause:

  • Impairments in cognition and memory
  • Loss of coordination
  • Blurred vision


Marijuana (cannabis) abuse is associated with increased risk of:

  • Depression
  • Anxiety
  • Schizophrenia and related disorders (among those with a pre-existing disposition)
  • Cardiovascular problems (when combined with alcohol)


PCP abuse can cause:

  • Memory loss
  • Speech difficulties
  • Depression
  • Anxiety
  • Suicidal thoughts

Prescription stimulants

Prescription stimulants include amphetamine (Adderall, Dexedrine) and methylphenidate (Ritalin, Concerta). Although these drugs can be used safely under a doctor’s guidance, their use is considered abuse if they are used more frequently or in higher doses than a doctor recommends, or are used without a prescription. Abuse of prescription stimulants can cause:

  • Weight loss
  • Malnutrition
  • Anxiety
  • Paranoia
  • Hostility
  • Psychosis
  • High body temperature
  • Elevated blood pressure
  • Irregular heart beat
  • Seizures
  • Heart attack


Psychedelics include LSD, magic mushrooms (psilocybin), peyote cactus (mescaline), and ayahuasca (DMT), as well as a wide range of newer synthetic drugs. Long-term health consequences of using psychedelics can include:

  • Hallucinogen persisting perception disorder (HPPD), also known as “permafry.” HPPD causes psychedelic users to experience hallucinations or other perceptual distortions for weeks, months, or even years after they have stopped using hallucinogens. They may also experience “flashbacks,” or re-experience memories from their psychedelic use.
  • Persistent psychosis, characterized by disorganized thinking, mood swings, hallucinations, and paranoia.
  • A “bad trip,” in which the user’s psychedelic experience has themes of fear, loss of control, feeling overwhelmed, or other such negative states. The drugs can cause these feelings to last long after the drugs have worn off, leaving depression or anxiety that can last for weeks, months, or years.


Speed abuse can cause:

  • Impaired cognition and memory
  • Mood disturbances
  • Anxiety
  • Insomnia
  • Irritability
  • Confusion
  • Paranoia
  • Aggression
  • Hallucinations
  • Weight loss and malnourishment
  • Damage to the brain, heart, liver, kidneys, or lungs
  • Dental damage (from dry mouth and grinding teeth)
  • Skin sores (from scratching or picking)


Steroids, specifically androgenic anabolic steroids, can cause:

  • Liver damage
  • Cardiovascular disease
    • High blood pressure
    • Decreases in HDL (“good” cholesterol)
    • Increases in LDL (“bad” cholesterol)
    • Enlarged heart
    • Stiffened arteries
  • Additional effects for males:
    • Baldness
    • Shrunken testicles
    • Reduced sperm count
    • Infertility
    • Increased risk for prostate cancer
    • Development of breasts
  • Additional effects for females:
    • Growth of facial and body hair
    • Baldness
    • Altered or stopped menstrual cycle
    • Enlarged clitoris
    • Deeper voice


Tobacco is inherently carcinogenic, apart from the carcinogens produced by smoking it. Use of smokeless tobacco, such as e-cigarettes, chewing tobacco, or snuff, is still associated with:

  • Cancer of the mouth, tongue, gum, cheek, throat, esophagus, stomach, and pancreas
  • Increased risk of heart disease, heart attack, or stroke
  • Mouth sores
  • Receding gums
  • Tooth damage

Drugs and pregnancy

When a pregnant woman uses drugs, so does the developing fetus. If the drugs are addictive, whether legal or illegal, then the child can be born addicted to them. If medical professionals do not manage this condition properly, then the child can experience neonatal abstinence syndrome, or neonatal withdrawal. This includes the same withdrawal symptoms that an adult would experience, which can be much more severe in a newborn.

Use of drugs while pregnant can also cause a variety of effects.


  • Miscarriage or stillbirth
  • Premature delivery
  • Cerebral palsy
  • Fetal alcohol spectrum disorders, including fetal alcohol disorder, characterized by:
  • Low birth weight
  • Learning problems
  • Problems with speech and cognition
  • Problems with attention and behavior
  • Problems with balance and movement
  • Poor muscle tone
  • Poor growth
  • Heart, kidney, or lung defects
  • Changes to the shape of the face


  • Miscarriage
  • Separation of the placenta from the lining of the womb
  • Premature birth
  • Low birth weight
  • Increased risk of sudden infant death syndrome (SIDS)
  • Increased risk for ADHD, conduct disorder, and obesity
  • Increased risk of being smokers as adults


  • Abnormal fetal brain development
  • Impairments in problem solving, planning, attention, and memory
  • Impulsivity
  • Depression
  • Increased risk of using tobacco or marijuana later in life


  • Low birth weight
  • Smaller head size
  • Shorter birth length
  • Subtle but significant differences in attention, organization skills, language, self-control, and abstract thinking


  • Detachment of the placenta from the lining of the womb
  • Premature delivery
  • Low birth weight
  • Heart and brain defects
  • Sleep and wakefulness problems
  • Increased sensitivity to stress
  • Subtle but significant impairments in attention


  • Miscarriage
  • Detachment of the placenta from the lining of the womb
  • Restricted fetal growth
  • Premature delivery

Getting help for addiction

Drug abuse can take a terrible toll on the body, and we want to help you or your loved one get clean quickly and safely. Using our progressive, specialized treatment plans, we’ll guide you on the path to rebuilding a new, drug-free life. Call us today to speak to our trained intake specialists to learn more about what we can do for you.

Medical Disclaimer

The Recovery Village aims to improve the quality of life for people struggling with substance use or mental health disorder with fact-based content about the nature of behavioral health conditions, treatment options and their related outcomes. We publish material that is researched, cited, edited and reviewed by licensed medical professionals. The information we provide is not intended to be a substitute for professional medical advice, diagnosis or treatment. It should not be used in place of the advice of your physician or other qualified healthcare providers.