You may not always notice when someone is under the influence. Subtle cues can slip by even the most attentive friend or family member. Recognizing the signs someone is high helps you keep your loved one safe and know when to step in or seek professional support. In this guide you’ll learn unexpected indicators—from physical and behavioral shifts to cognitive and environmental clues—that suggest someone is high, along with clear steps you can take to help.
Observe physical indicators
When someone is high, their body often gives it away. You may find yourself focusing on the obvious—red eyes or a dazed expression—but look a little closer and you’ll spot additional signs.
Eye and skin signs
- Bloodshot or glassy eyes, often paired with dilated pupils
- Dry mouth or “cottonmouth,” leading to frequent water breaks
- Flushed or pale skin, depending on substance and dosage
These cues are common with cannabis, but you may see them with other drugs too. If you want more detail on typical cannabis signs, check out our guide on how to tell if someone is high.
Coordination and movement
- Poor balance or unsteady gait
- Slowed reaction times, bumping into objects
- Tremors or involuntary muscle twitches
THC affects the cerebellum and basal ganglia, leading to unsteady movements and slowed responses [1]. These impairments vary by potency and user tolerance.
Appetite and vital signs
- Sudden onset of the “munchies,” craving snacks you wouldn’t normally eat
- Increased heart rate or racing pulse
- Fluctuating breathing patterns, from slow and drawn out to rapid
These shifts often accompany a marijuana high, which can last several hours but may leave traces of THC in the body for days or even months, depending on the drug test used [2].
Lingering odors
- A skunk-like or earthy smell clinging to hair or clothing
- Unusual fragrances masking the odor, such as incense or strong cologne
The distinctive aroma of marijuana can be stubborn. Even if someone showers, the scent may remain in textiles or hair [2].
Detect behavioral shifts
Drugs don’t just alter the body—they change behavior. You might attribute certain patterns to stress or fatigue, but persistent shifts can signal substance use.
Personal care and hygiene
- Neglecting grooming, wearing unwashed clothes
- Unusual body odor or disregard for cleanliness
- Skipping meals or irregular eating routines
When substance use becomes a priority, everyday tasks like showering or brushing teeth may fall by the wayside [3].
Responsibility and performance
- Missing deadlines at work or school
- Neglecting household chores or bills
- Frequent “forgotten” commitments or appointments
If you notice a pattern of excuses—“I’m just stressed” or “I overslept again”—it’s worth considering that drug effects might be at play.
Sleep and energy patterns
- Insomnia one night, excessive drowsiness the next
- Unusual napping, “zoning out” mid-conversation
- Difficulty waking up or staying alert
Erratic sleep often accompanies withdrawal and rebound effects, driving some individuals back to use just to reset their system [2].
Financial and legal red flags
- Unexplained cash shortages or frequent borrowing
- Losing items of value or selling belongings
- Risky behaviors like driving under the influence
Substance use can be expensive. Keep an eye on sudden financial stress or legal troubles that hint at deeper issues.
Notice cognitive changes
Intoxication and early addiction often impair thinking. You may pick up on memory lapses or altered judgment if you know what to watch for.
Memory and focus issues
- Forgetting recent conversations or tasks
- Difficulty following a storyline or instructions
- Frequently losing track of personal items
Short-term memory can decline sharply when someone is high, affecting even simple tasks.
Time perception distortions
- Slowing down or speeding up sense of time
- Complaints that hours feel like minutes, or vice versa
- Arriving early or late without realizing it
Because drugs interact with brain regions that process time, you might see people underestimate or overestimate elapsed minutes.
Executive function decline
- Poor decision-making, choosing immediate relief over long-term goals
- Trouble planning or organizing activities
- Impulsive actions, such as sudden travel or unplanned spending
These deficits aren’t limited to cannabis. Stimulants and sedatives alike can disrupt higher-order thinking [1].
Understand psychological effects
Beyond visible signs and behavior, drug highs can shift mood and perception in ways you might miss until they escalate.
Mood swings and euphoria
- Rapid transitions from tension to relaxation
- Unexplained bursts of laughter or intense talkativeness
- Moments of calm followed by irritability
These swings may be mistaken for anxiety or bipolar symptoms, but they often track with substance peaks and valleys.
Anxiety and panic episodes
- Sudden bouts of paranoia, especially in unfamiliar settings
- Racing thoughts or feelings of imminent danger
- Avoidance of crowds or places that feel “too stimulating”
High-THC cannabis carries a small but real risk of inducing panic or anxiety crises [2].
Psychotic symptoms and hallucinations
- Hearing or seeing things that aren’t there
- Disconnected or fragmented thoughts
- Suspiciousness that edges into delusional beliefs
Use of potent cannabis strains is linked to psychotic symptoms in about one in 100 users, and repeated episodes can increase risk for long-term psychiatric disorders [2]. If you observe these signs, it’s critical to seek medical help immediately.
Identify environmental warning signs
You don’t have to catch someone in the act. Their surroundings often reveal drug use habits and access points.
Drug paraphernalia
- Pipes, rolling papers, bongs, or vape pens
- Small baggies, tin foil, or homemade syringes
- Odd containers labeled as “edibles” or “tinctures”
The type of equipment varies by substance. For stimulant use like cocaine, see our page on signs of cocaine abuse and cocaine use symptoms.
Changes in social circle
- New friendships centered around substance use
- Isolation from longtime friends and family
- Frequent visitors at odd hours under the guise of “hanging out”
Shifting peer groups can normalize risky behaviors and make use harder to detect.
Secretive storage and behavior
- Stashed pills or powders hidden in odd places
- Locked boxes, backpacks kept under the bed
- Deleting messages or using multiple phone apps
These behaviors often accompany deeper patterns of misuse and avoidance.
Take appropriate actions
Spotting signs is only the first step. How you respond can make a difference in keeping your loved one safe and supported.
Approach with empathy
- Speak calmly, pick a private setting, and express concern rather than accusation
- Use “I” statements: “I’ve noticed you seem anxious lately” instead of “You’re always high”
- Listen more than lecture and validate their feelings
A non-judgmental conversation lowers defenses and opens pathways to help.
Encourage professional help
- Suggest a medical evaluation if you see severe anxiety, psychosis, or overdose risk
- Offer to research local therapists, rehab centers, or support groups together
- Highlight resources like crisis hotlines or peer-led programs
If you’re unsure where to start, talking with a primary care provider or calling a local helpline can guide you.
Consider sober living options
- Inpatient or outpatient programs provide structure and peer support
- Sober living homes offer a drug-free environment with accountability
- Aftercare plans, including therapy and support meetings, reduce relapse risk
Sober living can be a stabilizing next step for someone ready to make a change. It builds routines and healthy habits that support long-term recovery.
When to seek immediate help
If you observe any of the following, call emergency services or take your loved one to the nearest emergency department:
- Unresponsive or difficult to rouse
- Slowed breathing (fewer than eight breaths per minute) or choking sounds
- Seizures, severe agitation, or uncontrollable vomiting
- Self-harm thoughts or threats
Quick intervention can prevent overdose fatalities and long-term harm.
By tuning in to these unexpected signs someone is high, you’ll be better equipped to offer help and guide your loved one toward safety. Early recognition, combined with empathy and professional support, can turn a moment of concern into a pathway for recovery.
