What Are Signs of Addiction?

someone taking many pills

Addiction is a devastating disease that has far-reaching consequences. Individuals who are addicted suffer from physical and mental health problems, some of which may be life-threatening. Addiction can be harmful to families and marriages. It is also a public health crisis that affects entire communities.1

What are signs of addiction? If you decide to become a substance use counselor, part of your job will be to educate families and communities about recognizing the signs of common and uncommon addictions. Some of these may seem obvious, while others are far subtler.

In This Article:

The Nature of Common and Uncommon Addictions

What is the difference between drug abuse and a common or uncommon addiction? When someone has an addiction, this means that they do not have control over how they use or misuse a substance or perform a behavior. A person with a drug addiction has a dependency on a substance that causes them to rely on its use to cope with everyday life.2

In the case of addiction, there is a physical/psychological component involved that leaves the affected person unable to control aspects of the addiction. Drug abuse, on the other hand, does not include a state of dependence on the substance. Despite this, even drug abuse can cause significant harm.2

Signs of Addiction and Withdrawal

The indications of a substance addiction can vary between individuals and be affected by their personal circumstances, genetics and the substance that they are using. A person with an addiction may be unable to stop even after a serious attempt to quit. If they do try to quit, they may experience withdrawal symptoms.

Some common withdrawal symptoms include the following:3

  • Muscle pain
  • Nausea and vomiting
  • Insomnia
  • Sweating
  • Shaking and tremors
  • Chills or shivering
  • Changes in mood and appetite
  • Fatigue
  • Irritability

In severe cases, it’s possible to experience hallucinations, delirium and even seizures.3

Behavior and Personality Signs of Drug Addiction

It is common for drug addiction to cause changes in behavior and personality. Families may notice that their loved ones become uncharacteristically irritable, anxious and belligerent. Occasionally, drug addiction can result in combativeness and perhaps even violence. Drug addicts may display any of the following:4

  • Impaired judgment
  • Impulsivity
  • Paranoia
  • Restlessness
  • Lack of inhibition
  • Mood swings

Many families also notice that their loved ones have begun neglecting personal grooming habits. They may forget to brush their hair or teeth, or they might wear the same clothes on multiple consecutive days.5

Physical Signs of Addiction

Addiction counselors often work with families who seek help after realizing that their children or other loved ones have begun showing physical changes that might indicate drug abuse. Some of the common physical signs of addiction include the following:5

  • Sudden, unexplained weight loss or gain
  • Insomnia
  • Bloodshot eyes or dilated pupils
  • Unusual odors that emanate from the breath or clothing
  • Shakiness and tremors
  • Involuntary eye movements
  • Dizziness
  • Rapid breathing or slowed breathing
  • Nausea or vomiting

Some drugs can cause chronic nasal congestion, such as those that are snorted. Methamphetamine can cause “meth mouth” with continued use, and is characterized by gum disease, mouth sores and rotting teeth.5

Social Connectivity

It’s important to note that drug addiction doesn’t only affect a person’s physical health and personality. What are signs of addiction beyond physical and behavioral changes? To begin with, it’s common for drug addicts to change the way they interact with others and who they interact with.

For example, drug addicts often stop socializing with their usual friends, and instead begin associating with other drug abusers or dealers. They may also behave in ways that alienate their old friends. Addicts often withdraw from their usual social activities, perhaps without being able to provide a reasonable explanation for it.5

Hallucinations and Flashbacks

A hallucination is seeing, hearing or smelling something that is not there. Not every drug abuser will experience hallucinations, although many drugs can cause them. Synthetic cannabinoids (K2 or Spice), substituted cathinones (bath salts) and stimulants such as methamphetamine, amphetamine and cocaine can all potentially cause hallucinations.5

Club drugs like Ecstasy and hallucinogens like LSD and PCP are other examples. Additionally, LSD can result in flashbacks. These refer to the re-experiencing of the hallucinations. Flashbacks can occur years afterward.5

Lifestyle and Functional Abilities

Not all substance abusers experience a complete breakdown of functional abilities. Many of them, including a significant percentage of alcoholics, are able to go about their daily business. They go to work or school, pay their bills and take care of their domestic responsibilities.6

Over time, however, functional abilities and lifestyle can start to break down. People suffering from drug addictions often experience financial problems, which might lead them to steal or borrow money irresponsibly. They may experience job loss and legal problems. Drug addiction is characterized by the continued use of the drug, despite these serious problems.5

If you feel called to address the signs of drug addiction in others and guide families toward a better future, you might consider pursuing a career in psychology and counseling. Grand Canyon University is pleased to offer both bachelor’s and master’s degrees that focus on substance abuse and addiction. Complete the form on this page to learn more about joining our Christian learning community.


1 American Public Health Association. (n.d.). Substance misuse. Retrieved July 14, 2023.

2 American Psychological Association. (n.d.). Substance use, abuse, and addiction. Retrieved July 14, 2023. 

3 T.,B. (2022, November 7). What is withdrawal? VeryWellMind. Retrieved July 14, 2023.

4 Gateway Foundation. (February 8). 10 ways substance addiction can change your personality. Retrieved July 14, 2023.

5 Mayo Clinic Staff. (2022, October 4). Drug addiction (substance use disorder). Retrieved July 14, 2023.

6 Bienvenu, M. (2023, May 1). Are you a high-functioning alcoholic. WebMD. Retrieved July 14, 2023.

Approved by the graduate counseling programs manager of the College of Humanities and Social Sciences on Aug. 28, 2023.

The views and opinions expressed in this article are those of the author’s and do not necessarily reflect the official policy or position of Grand Canyon University. Any sources cited were accurate as of the publish date.