Substance use disorders manifest in a variety of ways and can change throughout the course of the illness. Not everyone will experience every symptom, and recognizing even subtle changes from a person’s baseline behavior is vital. It’s important to remember that people with SUDs often go to great lengths to hide their substance use, so vigilance is necessary. Here’s a breakdown of the signs to look out for:

Physical Signs and Symptoms

  • Bloodshot eyes, dilated or constricted pupils
  • Changes in appetite, weight loss or weight gain
  • Sleep problems: insomnia or excessive sleepiness
  • Neglecting personal hygiene or changes in appearance
  • Slurred speech, difficulty with coordination
  • Tremors, sweating, unexplained bruises or injuries
  • Frequent nosebleeds or runny nose (could indicate snorting drugs)
  • Needle marks (in cases of intravenous drug use)

Behavioral Changes

  • Preoccupation with obtaining and using the substance
  • Secretive behavior or spending time with new social groups
  • Changes in school or work performance: unexplained absences, slipping grades, decreased productivity
  • Social withdrawal: Isolating themselves from friends or family, losing interest in hobbies or activities they once enjoyed
  • Financial problems: Borrowing or stealing money, inability to manage finances
  • Mood swings, increased irritability, outbursts of anger
  • Risky behaviors: Driving while intoxicated, engaging in unsafe sexual practices, or other impulsive actions
  • Legal problems: Arrests, DUI charges, or other substance-related legal issues

Psychological and Emotional Signs

  • Intense cravings for the substance
  • Periods of intoxication or showing signs of withdrawal
  • Difficulty managing emotions: Increased anxiety, depression, apathy
  • Denial of the problem: Minimizing the extent of use or the negative impact it has on their lives
  • Changes in personality, seeming like ‘a different person’ when using
  • Lack of motivation or an inability to follow through on commitments
  • Memory problems and difficulty concentrating

Important Considerations

  • Subtle changes matter: Don’t dismiss slight behavioral shifts or attribute them solely to typical moodiness or stress. Pay attention to patterns that deviate from someone’s usual way of being.
  • Not just about quantity: The frequency of use is less important than the negative consequences resulting from substance use.
  • Age-dependent signs: Signs might differ between adults and adolescents and need to be considered within the context of developmentally typical behavior
  • Co-occurring disorders: Signs of SUDs might overlap with symptoms of a mental health condition like depression or anxiety, making it essential to seek professional assessment.

While these signs might feel overwhelming, it’s important to remember that seeking help as early as possible offers the best chance for a successful recovery. Even when someone is reluctant, expressing your concern and showing support can plant the seed for them to consider change. If you’re worried about yourself or someone you care about, the following pages will explore when to seek professional help and the different treatment options available.


The content provided herein is intended for informational purposes only and should not be considered a substitute for professional advice or treatment. If you or someone you know is struggling with mental health-related concerns, seek guidance from a qualified behavioral health professional. Click here to get help now. Any links are provided as a resource and no assurance is given as to the accuracy of information on linked pages.