Signs of Drug Use
Identifying drug use in safety-sensitive employees is essential to maintaining a safe work environment and complying with DOT regulations. Drug use can present through a range of physical, behavioral, and psychological indicators. Supervisors are not expected to diagnose substance use disorders, but they must be trained to recognize observable signs and symptoms that could justify a reasonable suspicion drug test.
Below are the most common signs of drug use, with expanded explanations to improve observation and reporting skills:
1. Dilated or Pinpoint Pupils
Drug use often affects the autonomic nervous system, which controls pupil size. Abnormal pupil responses may include:
- Dilated pupils (large and unresponsive to light) — common with stimulant use (e.g., cocaine, methamphetamines, ecstasy, prescription stimulants).
- Pinpoint pupils (very small, constricted) — commonly associated with opioid use (e.g., heroin, morphine, oxycodone, fentanyl).
These signs are especially significant in well-lit environments where pupils should naturally constrict. A supervisor noticing abnormal pupil size should make note of lighting conditions and any difficulty the employee has with vision or focus.
2. Nervousness, Paranoia, or Hyperactivity
Psychoactive substances can alter mood, energy, and perception. Behavioral symptoms to watch for include:
- Rapid, pressured speech or excessive talking
- Pacing, jitteriness, or inability to sit still
- Unprovoked suspicion or fear (paranoia)
- Irrational fears, looking over their shoulder, or reacting to stimuli that aren’t present
- Sudden mood swings or emotional outbursts
These behaviors may indicate use of stimulants, hallucinogens, or synthetic drugs and can pose serious safety concerns on the job.
3. Slow or Incoherent Speech
Certain drugs, especially depressants (such as opioids, benzodiazepines, or barbiturates), may suppress the central nervous system and result in:
- Slurred, mumbled, or monotone speech
- Delayed responses or inability to complete sentences
- Confused or disorganized thoughts
- Repeating words or phrases without context
These indicators, especially when accompanied by other physical signs, can suggest impairment serious enough to compromise workplace safety.
4. Excessive Sweating or Chills
Drug use can affect body temperature regulation, causing physiological symptoms such as:
- Profuse sweating without physical exertion
- Complaints of feeling excessively hot or cold
- Visible tremors or goosebumps
- Unusual body odor or clammy skin
These symptoms can result from a variety of substances, including stimulants, opioids, and synthetic drugs. The presence of these symptoms in an otherwise climate-controlled setting is a strong warning sign.
5. Unexplained Drowsiness or Alertness
Drugs may produce either sedative or stimulant effects. Supervisors should look for:
- Excessive sleepiness, nodding off, or appearing disoriented
- Frequent yawning, glassy eyes, or slow blinking
- Sudden bursts of energy or over-alertness, often without obvious cause
- Inconsistent attention span, restlessness, or fidgeting
When these signs interfere with normal work duties or safety awareness, they warrant documentation and potential reasonable suspicion testing.
6. Track Marks, Nosebleeds, or Physical Disorientation
Visible physical signs may indicate drug use by route of administration. Supervisors should never perform physical examinations but may observe:
- Track marks: puncture wounds or bruising on arms, hands, legs, or neck from intravenous drug use
- Nosebleeds: frequent or unexplained nasal bleeding, irritation, or sniffing, which may be associated with snorting substances
- Physical disorientation: difficulty standing upright, bumping into objects, or appearing confused about surroundings
These signs are especially important when the employee is in a safety-sensitive role, such as operating vehicles, heavy equipment, or handling hazardous materials.
Final Reminder for Supervisors:
If one or more of these signs is observed, especially in combination, it may constitute reasonable suspicion of drug use and justify testing under DOT regulations. Supervisors must:
- Document all observations objectively and thoroughly
- Avoid assumptions or accusations
- Follow the company’s drug testing and reasonable suspicion protocol promptly
Early recognition and timely action not only ensure DOT compliance—they help protect lives, prevent incidents, and maintain a healthy and accountable work environment.