Drug use can have a wide range of short and long-term effects. These effects often depend on the specific drug or drugs used, how they are taken, how much is taken, the person’s health, and other factors. Short-term effects can range from changes in appetite, wakefulness, heart rate, blood pressure, and/or mood to heart attack, stroke, psychosis, overdose, and even death. These health effects may occur after just one use.

Longer-term effects can include heart or lung disease, cancer, mental illness, HIV/AIDS, hepatitis, and others. Long-term drug use can also lead to addiction. Drug addition is a brain disorder. Not everyone who uses drugs will become addicted, but for some, drug use can change how certain brain circuits work. These brain changes interfere with how people experience normal pleasures in life such as food, their ability to control their stress level, their decision-making, their ability to learn and remember, etc. These changes make it much more difficult for someone to stop taking drug even when it’s having negative effects in their life and they want to quit.

Drug use can also have indirect effects on both the people who are taking drugs and on those around them. This can include affecting a person’s nutrition; sleep; decision-making and impulsivity; and risk for trauma, violence, injury and communicable diseases. Broader negative outcomes may be seen in education levels, employment, housing, relationships and criminal justice involvement.

HIV, Hepatitis, and Other Infections Diseases

Drug use is linked to risky behaviors such as needle sharing and can also weaken the immune system. This combination greatly increases the likelihood of contracting HIV, hepatitis and other infectious diseases.

Drugs that are commonly injected and can lead to HIV, hepatitis and other infectious diseases:

• Cocaine
• Heroin
• Methamphetamine
• Prescriptions Opioids
• Steroids

Caner

Cigarette smoking is the most preventable cause in the United States. Smoking cigarettes has been linked to cancer of the mouth, neck, stomach, and lungs, among others. Nonsmoking people exposed to secondhand cigarette smoke increase their changes of developing lung cancer in addition to other health problems.

Young adult males who use marijuana and began their use during adolescence are at risk for an aggressive form of testicular cancer.

Drugs that may cause cancer:

• Marijuana
• Steroids
• Tobacco

Cardiovascular Effects

Researchers have found that most drugs can have adverse cardiovascular effects, ranging from abnormal heart rate to heart attack. Injections drug use can also lead to cardiovascular problems such as collapsed veins and bacterial infections of the blood vessels and heart valves.

Drugs that can affect the cardiovascular system:

• Cocaine
• DMT
• GHB
• Heroin
• Inhalants
• Ketamine
• Khat
• LSD
• Marijuana
• MDMA
• Mescaline
• Methamphetamine
• PCP
• Prescription Stimulants
• Steroids
• Synthetic Cannabinoids
• Synthetic Cathinones
• Tobacco

Respiratory Effects

Drug use can lead to a variety of respiratory problems. Smoking cigarettes, for example, has been shown to cause bronchitis, emphysema, and lung cancer. Marijuana smoke can also cause respiratory problems including, chronic bronchitis. Smoking crack cocaine can also cause lung damage and severe respiratory problems. The use of some drugs, such as opioids, may cause breathing to slow, block air from entering the lungs, or make asthma symptoms worse.

Drugs that can affect the respiratory system:

• Cocaine
• DXM
• GHB
• Heroin
• Inhalants
• Ketamine
• Marijuana
• PCP
• Prescription Opioids
• Tobacco

Gastrointestinal Effects

Among other adverse effects, many drugs can cause nausea and vomiting after use. Cocaine use can also cause abdominal pain and bowel tissue decay, and opioid use can cause abdominal pain, acid reflux, and serve constipation.

Drugs that can affect the gastrointestinal system:

• Cocaine
• DXM
• GHB
• Heroin
• Khat
• Kratom
• LSD
• MDMA
• Mescaline
• Nicotine
• PCP
• Prescription Opioids
• Psilocybin
• Synthetic Cannabinoids
• Synthetic Cathinones

Musculoskeletal Effects

Steroid use during childhood or adolescence, resulting in high hormone levels, can signal the bones to stop growing earlier than they normally would, leading to short stature. Other drugs may also cause severe muscle cramping and overall muscle weakness.

Drugs that can affect the musculoskeletal system:

• Inhalants
• MDMA
• PCP
• Psilocybin
• Rohypnol
• Steroids
• Synthetic Cathinones

Kidney Damage

Some drugs may cause kidney damage or failure, either directly or indirectly, from dehydration, dangerous increases in body temperature, and muscle breakdown.

Drugs that can cause kidney damage:

• Heroin
• Ketamine
• Inhalants
• MDMA
• PCP
• Steroids
• Synthetic Cannabinoids

Liver Damage

Chronic use of some drugs, such as heroin, inhalants, steroids and alcohol may lead to significant damage to the liver. This damage can be worse when these are combined.

Drugs that can cause liver damage:

• DXM
• Heroin
• Inhalants
• Steroids

Neurological Effects

All addictive drugs act in the brain to produce their euphoric effects. However, some can also cause damage due to seizures, stroke and direct toxic effects on brain cells. Drug use can also lead to addiction, a brain disorder that occurs when repeated drug use leads to changes in the function of multiple brain circuits that control pleasures/reward, stress, decision-making, impulse control, learning and memory, and other functions. These changes make it hard for those with an addiction to experience pleasure in response to natural rewards or to manage their stress, control their impulses, and make the healthy choices to stop drug seeking and use.

Drugs that can cause neurological problems:

• Ayahuasca
• Cocaine
• DMT
• DXM
• GHB
• Heroin
• Inhalants
• Ketamine
• Khat
• Kratom
• LSD
• Marijuana
• MDMA
• Mescaline
• Methamphetamine
• PCP
• Prescription Opioids
• Prescription Sedatives
• Prescription Stimulants
• Psilocybin
• Rohypnol
• Salvia
• Steroids
• Synthetic Cannabinoids
• Synthetic Cathinones
• Tobacco/Nicotine

Other Health Effects

In addition to the effects that various drugs may have on specific organs of the body, many drugs produce global body changes such as dramatic changes in appetite and increases in body temperature, which may impact a variety of health conditions. Withdrawal from drug use also may lead to numerous adverse health effects, including restlessness, mood swings, fatigue, changes in appetite, muscle and bone pain, mental health problems, insomnia, cold flashes, diarrhea, vomiting, and others.

Drugs that have global adverse health effects:

• Cocaine
• Heroin
• Inhalants
• Marijuana
• MDMA
• Methamphetamine
• Nicotine
• Prescription Sedatives
• Prescription Opioids
• Prescription Stimulants
• Steroids

Mental Health Effects

Chronis use of some drugs can lead to both short and long-term changes in the brain, which can lead to mental health issues including paranoia, depression, anxiety, aggression, hallucinations and other problems.

Many people who are addicted to drugs are also diagnosed with other mental disorders and vice versa, Compared with the general populations, people addicted to drugs are roughly twice as likely to suffer from mood and anxiety disorders, with the reverse also true.

Drugs that can cause mental health problems:

• Cocaine
• Inhalants
• Ketamine
• Kratom
• LSD
• Marijuana
• MDMA
• Methamphetamine
• PCP
• Prescription Stimulants
• Steroids

Sources: https://www.drugabuse.gov/related-topics/health-consequences-drug-misuse