The terms “narcotics” and “opioids” are both commonly used, but the preferred term in medical and legal contexts is now “opioids.” Opioids are primarily used for pain relief.

According to the Centers for Disease Control and Prevention (CDC), people used to refer to drugs as “narcotics” if they relieved pain and dulled the senses. These could be natural or synthetic drugs that worked in the nervous system and the brain to reduce pain.

Most opioids can be legally prescribed by doctors, but they can also be misused or distributed illegally. Some opioids, such as heroin, have no medical function and are illegal to use or distribute except in medical research.

This article will explain the purpose of narcotics or opioids, along with the types, benefits, and risks.

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“Opioid” is an umbrella term referring to the natural, synthetic, or semi-synthetic chemicals that work in the nervous system or specific receptors in the brain to reduce pain. Some people still use the term “narcotics” to refer to all illegal drugs, but this is now inaccurate in both medical and legal usage.

According to the CDC and the Drug Enforcement Agency (DEA), the correct term is now “opioids.” The term “narcotics,” used accurately, refers only to opioids.

Opioids are drugs that are either made from natural substances found in the opium poppy plant or manufactured synthetically to mimic the structure of natural opium.

The term “opioids” covers all types of opioid drugs. A similar term, “opiates,” includes only natural opioids such as heroin or morphine.

Opioids fall into four categories. All of these, except heroin, can be legally prescribed for medical purposes. However, legal opioids are also sold illegally outside a doctor’s supervision. Heroin is one opioid that is illegal to make, sell, or use.

  • Heroin: This is an illegal opioid synthesized from morphine.
  • Natural opioids: These include heroin, morphine, and codeine.
  • Synthetic opioids: These include medications such as tramadol and fentanyl. Methadone is a synthetic opioid often used under medical supervision to help manage opioid use disorder.
  • Semi-synthetic opioids: These include drugs such as oxycodone (OxyContin), hydrocodone (Vicodin), hydromorphone, and oxymorphone.

Legally, opioids are controlled substances classified from Schedule I to Schedule V depending on their medical usefulness and potential for dependence. Doctors can legally prescribe most, except for some Schedule I opioids, such as heroin.

Read more about opioids here.

Prescription opioids are for managing pain after surgery or injury or for health conditions such as cancer. Increasingly, doctors are prescribing opioids for noncancer pain, such as chronic back pain, osteoarthritis, or coughing.

Some people use opioids illegally for the euphoria, or “high,” they can produce. Opioid drugs can cause addiction or opioid use disorder (OUD).


Opioids can help the body relax and relieve symptoms of a serious illness like cancer, injury, or pain from a surgical procedure. When a person uses opioids as prescribed and directed by a doctor, they can help with:

  • pain after surgery
  • severe pain due to injury
  • pain from cancer
  • palliative or end-of-life care

Prescription opioids are usually safe when taken for a short time under a doctor’s supervision. However, they also have the potential to cause mental and physical dependence.

Opioids are highly addictive because they can trigger and release endorphins that make the brain feel pain relief. Since opioids can produce euphoria, and because the body can become habituated to them and produce withdrawal symptoms when a person reduces the drug, people sometimes misuse them. This can lead to opioid use disorder.

Taking too many opioids can cause breathing problems and unconsciousness, which is an overdose. Not all overdoses result in death, but many do. According to the CDC, 75% of the nearly 92,000 drug overdose deaths in the United States involved an opioid.

Side effects

In addition to the risks of addiction, misuse, and overdose, opioid use can have many side effects, even when taken under a doctor’s direction. Side effects may include:

  • tolerance, or a reduced response to a drug with repeated use
  • physical dependence, which is when a person adapts to a drug and experiences symptoms of withdrawal after stopping it
  • increased pain sensitivity
  • depression
  • sleepiness or dizziness
  • confusion
  • nausea or vomiting

Some of the language around opioid use can be confusing. Here is how the CDC clarifies three terms often used to describe a person’s progressive dependence on opioids.

  • Opioid tolerance: Tolerance is when a person begins to “tolerate” a drug. They get a reduced effect from the amount they had been taking and need to take more of the drug to get the same initial effect.
  • Opioid dependence: Dependence is when a person experiences physical symptoms if they stop the medication. This is because the body has adapted to regular opioid use.
  • Opioid addiction: The hallmark feature of addiction is that a person tries and fails to cut down or control use, despite it causing problems at work, school, or home. Opioid addiction usually follows the tolerance and dependence stages.

The Diagnostic and Statistical Manual of Mental Disorders, 5th edition, text revision (DSM-5-TR) describes OUD as a “problematic pattern of opioid use leading to clinically significant impairment or distress.”

OUD can occur at either the dependence or addiction phases of opioid use, with addiction being the more severe. However, modern researchers are quick to point out that opioid dependence is not the same as addiction. Physical dependence is a natural consequence of taking medications such as opioids long term, while addiction is continued use even with negative effects.

A clinical OUD diagnosis requires that a person experience multiple problems from opioid use, such as:

  • opioid-related problems at work, school, or home
  • withdrawal symptoms when attempting to cut down on or stop opioid use
  • missed life events in favor of opioid use
  • excessive time spent using or obtaining opioids

Anyone who takes opioids can develop OUD over time. In 2016, more than 11.5 million Americans reported misusing prescription opioids.

Opioid replacement therapy

A doctor can treat OUD with opioid replacement therapy using drugs such as buprenorphine or methadone. People with OUD also benefit from treatment, including 12-step programs, support groups, and individual and group therapy with mental health professionals.

If a person or their family member is seeking treatment for either acute or chronic pain, medical professionals recommend they talk with a physician about a multimodal and multidisciplinary approach to pain management. This means using different methods and different branches of healthcare to manage pain.

Many professional organizations agree that alternative treatments to opioids can often help people with acute or chronic pain avoid opioids or reduce their opioid dosage. These organizations include:

In its 2022 Guidelines for Prescribing Opioids for Chronic Pain, the CDC expressed its preference for non-opioid treatment of chronic pain.

“Opioids” is the preferred term, in both medical and legal contexts, for a class of drugs that work in the nervous system and specific receptors in the brain to reduce pain and cause relaxation and even euphoria. However, some people still use the term “narcotics.”

Under a doctor’s direction, opioids can help manage acute or chronic pain. If misused, they can lead to opioid use disorder, which can negatively affect physical and mental health, as well as home, work, and social life.

A doctor can treat opioid use disorder with the help of medications, as well as various treatment therapies and programs.