They thought they were having a stroke. Some feared they had eaten something toxic. Others simply had no idea what was happening. Accidental cannabis ingestion is behind a growing number of frightening hospital visits, and most patients never saw it coming. The culprit? A biscuit at a colleague’s leaving do, a sweet from a friend’s kitchen, or a CBD supplement that was anything but harmless.

A new scoping review published in The American Journal of Medicine confirms that unintentional THC exposure among adults happens more often than clinicians expect. And when it does, it looks a lot like a stroke.

Accidental Cannabis Ingestion: What Patients Actually Experience

Researchers analysed 16 studies covering 84 adult cases from the United States, Brazil, France, Slovenia, the Netherlands, and Turkey. Patients who had unknowingly consumed THC turned up in emergency departments with dizziness, dry mouth, confusion, vision changes, tingling in the limbs, nausea, slurred speech, anxiety, and extreme drowsiness.

High blood pressure, memory problems, poor coordination, and a racing heart were also common. Doctors often suspected stroke first. Food poisoning came up as another early guess.

In most cases, patients had no idea they had consumed anything psychoactive. THC-laced baked goods and sweets were the most frequent source. Some patients had bought what they believed were CBD-only supplements. Those products, it turned out, contained THC or synthetic cannabinoids.

A Problem Growing Alongside Legalisation

Cannabis is no longer a niche product. In 2025, Americans spent an estimated $34 billion on legal cannabis sales. Around 47.5% of American adults have tried cannabis at some point in their lives, and 22.3% did so in the past year. Roughly 74% of Americans now live in a state where cannabis is legal for medical or recreational use.

As cannabis products appear more frequently in food at social events, the risk of accidental cannabis ingestion grows with them. People do not need to seek out cannabis to be exposed to it.

Older adults face particular risk. The reviewed cases spanned patients aged 18 to 94. Researchers noted that symptoms can be more severe in older patients and may interact with existing health conditions or medications. A person in their 70s who feels suddenly confused and unsteady after eating homemade cake at a family gathering is unlikely to think cannabis. But it may well be the answer.

Unintentional THC Exposure: Why Doctors Keep Mistaking It for Stroke

Unintentional THC exposure can look strikingly like a stroke. Patients arrive unable to speak clearly, with altered consciousness, visual disturbances, and elevated blood pressure. Without any reason to suspect cannabis, doctors move straight to stroke protocols.

The distinction matters. Unlike a typical stroke, accidental cannabis ingestion does not usually produce focal neurological deficits. There is no one-sided weakness, no facial drooping. When confusion comes alongside nausea or vomiting, that combination should put cannabis on the list.

A positive THC urine screen, or a mention that the patient recently ate food someone else prepared, can shift the diagnosis entirely.

Researchers recommend that clinicians ask patients directly whether they ate food made by others, and whether they use any CBD products. The CBD market remains poorly regulated in many countries. Products that say CBD-only are not always what they claim.

Recovery and What Lingers

Most people recover within 24 hours. That is the finding from the review, and it offers some reassurance. But some patients reported that fatigue and anxiety stuck around for days or even weeks.

For people who do not drink or use substances, and who have strong personal reasons for keeping it that way, an unknowing unintentional THC exposure is more than a medical event. It is a violation of their autonomy. The distress does not end when the THC leaves the system.

Awareness Alone Is Not Enough

Researchers call for greater clinical awareness. But the issue stretches beyond hospital corridors.

Cannabis-containing food products need clearer and more consistent labelling. The CBD supplement market needs tighter regulation. And people sharing food at social events need to understand that spiking food with cannabis, even casually and even without harmful intent, can cause real harm.

Adults have the right to know what they consume. Removing that right carries consequences. Medical ones, legal ones, and personal ones.

Cases of unintentional THC exposure will keep rising as cannabis becomes more accessible. The question is whether awareness in clinics, in shops, and at dinner tables rises to meet it.

References

1. Massart A, Wills T, Kapuria M, et al. Unintentional ingestion of psychoactive cannabis products among adults: a scoping review. The American Journal of Medicine. 2026. https://doi.org/10.1016/j.amjmed.2026.02.023
2. Substance Abuse and Mental Health Services Administration (SAMHSA). Key substance use and mental health indicators in the United States: Results from the 2023 National Survey on Drug Use and Health. US Department of Health and Human Services; 2024.
3. BDSA Cannabis Market Intelligence. US legal cannabis market report 2025. BDSA; 2025.
4. MJBizDaily. US cannabis sales projections and state-by-state legalisation tracker. MJBizDaily Research; 2025.

Source: dbrecoveryresources