Being high from cannabis produces a recognizable set of physical, mental, and behavioral changes. Some are subtle, others are obvious, and they vary depending on how much was consumed and whether it was smoked or eaten. Here’s what to look for in yourself or someone else.
The Physical Signs
Red eyes are one of the most visible giveaways. Cannabis causes blood vessels in the eyes to expand, which makes the whites look pink or bloodshot. This happens regardless of whether cannabis is smoked, vaped, or eaten, so it’s not just from smoke irritation.
A dry mouth (sometimes called “cottonmouth”) is almost universal. Your mouth and throat feel sticky and parched, and no amount of swallowing seems to fix it. Increased appetite, often hitting 30 to 60 minutes in, is another classic sign. Foods taste more intense, and cravings can feel unusually strong.
Heart rate speeds up shortly after use, and blood pressure can temporarily rise. You may notice your heart beating faster than normal or feel a slight pounding in your chest, especially if you’re anxious. Pupil changes are less reliable as a marker. Some studies have found that cannabis slightly increases pupil size, while others report the opposite, so dilated or constricted pupils alone aren’t a definitive indicator.
How It Affects Your Thinking
The most consistently impaired mental abilities are short-term memory and the speed at which you process information. A meta-analysis covering more than 1,500 people found that verbal learning and memory, including the ability to take in, store, and recall new information, are the cognitive functions most disrupted by cannabis. You might lose your train of thought mid-sentence, forget what you were just talking about, or struggle to follow a conversation with multiple threads.
Working memory takes a hit too. Tasks that require holding several pieces of information in your head at once, like mental math or following directions, become noticeably harder. Reaction times slow down in a dose-dependent way: the more you consume, the slower you respond. Interestingly, accuracy on tasks without time pressure doesn’t drop as sharply, which means the high tends to slow you down more than it makes you wrong.
Time perception warps. Minutes can feel like they stretch out far longer than they actually last. This distortion is one of the most commonly reported subjective effects and one of the easiest ways to recognize a high in yourself.
Mood and Psychological Changes
The emotional range of being high is wide. Most people experience relaxation, mild euphoria, and sleepiness. Things feel funnier, music sounds better, and there’s a general sense of contentment. For many users, this is the entire experience.
But cannabis can also produce disorientation, anxiety, and paranoia, particularly at higher doses or in people who are less experienced. New users are more likely to feel panicky or uneasy. If someone seems unusually quiet, withdrawn, or is expressing irrational fears, that’s a sign the high has tipped into uncomfortable territory. At very high doses, confusion, agitation, delusions, and even brief hallucinations can occur, though these episodes typically resolve on their own.
Balance and Coordination
Cannabis measurably impairs motor control. In one study, arm movement speed dropped by about 15% immediately after use and stayed impaired an hour later. Leg speed decreased by 6 to 7% within the first hour. Balance also worsened right after use: body sway increased whether participants had their eyes open or closed, though balance tended to recover somewhat by the one-hour mark.
What this looks like in practice: slightly clumsy movements, unsteady walking, fumbling with objects, or difficulty with tasks that require hand-eye coordination. Fine finger movements (like tapping) seem less affected, so someone who is high may be able to text on their phone but struggle to catch something thrown at them.
Timing Matters: Smoking vs. Edibles
How cannabis was consumed changes when the signs appear and how long they last. With smoking or vaping, effects begin within seconds to a few minutes and peak around the 30-minute mark. The high then gradually fades over one to three hours.
Edibles are a completely different timeline. Effects don’t start until 30 minutes to 2 hours after eating, and they can peak as late as 4 hours in. This delay is why people sometimes eat more thinking the first dose “didn’t work,” only to find themselves much higher than intended once everything kicks in. If someone ate a cannabis edible and feels fine after 20 minutes, they are likely not yet feeling the full effects. The high from edibles also tends to be more intense and longer-lasting, sometimes stretching six hours or more.
Signs You’re Too High
Overconsumption, sometimes called “greening out,” involves a more extreme version of the symptoms above. The key markers are intense nausea or vomiting, severe anxiety or panic, confusion or disorientation, a racing heartbeat, and pronounced lethargy. Some people turn pale or feel faint from a drop in blood pressure when they try to stand up. Slurred speech, significant loss of coordination, and an inability to concentrate on anything are also common at this level.
Most episodes of overconsumption are deeply unpleasant but not medically dangerous, and they resolve within a few hours. However, uncontrollable vomiting, chest pain, extreme confusion, or difficulty breathing are signs that warrant calling for help. Children who accidentally ingest edibles are at higher risk for serious effects, including extreme drowsiness, muscle weakness, and breathing problems.
How to Come Down Faster
There’s no reliable way to instantly end a high, but a few strategies can take the edge off. Staying hydrated helps with dry mouth and general discomfort. Water, tea, or juice won’t speed up how fast your body processes THC, but feeling less physically uncomfortable can reduce anxiety.
CBD may help counteract some of the more unpleasant effects. It appears to work by blocking the same brain receptors that THC activates, potentially reducing feelings of intoxication, sedation, and racing heartbeat. If you have access to a CBD-only product, it’s one of the more evidence-backed options.
You may have heard that chewing black peppercorns can reduce a high. The idea comes from a compound in pepper called beta-caryophyllene, which has shown some anxiety-reducing effects in animal studies. Similarly, lemon and pine nuts contain compounds that could theoretically interact with the same brain pathways cannabis affects. But the human evidence for any of these is essentially nonexistent, so treat them as folk remedies rather than proven solutions. The most effective approach is finding a calm, comfortable environment, putting on something familiar to watch or listen to, and waiting it out.