When a person consumes too much cannabis, they may experience what is commonly referred to as a cannabis “overdose.” This term, often called “green out,” describes acute overconsumption leading to uncomfortable and distressing symptoms. Unlike overdoses from many other substances, a cannabis overdose is generally not life-threatening. The experience involves a range of unpleasant physical and psychological reactions due to excessive tetrahydrocannabinol (THC).
Recognizing the Signs
Consuming too much cannabis can lead to physical and psychological symptoms. Physical reactions often include a rapid heart rate, sometimes accompanied by chest pain, and a decrease in blood pressure. Nausea and vomiting are common, along with sweating, clammy skin, and tremors. Individuals might also experience difficulty coordinating movements, slurred speech, and general lethargy.
The psychological effects can be particularly distressing, including intense anxiety, paranoia, and panic attacks. Some individuals may experience disorientation, impaired judgment, or a feeling of being overwhelmed. While less common, very high doses can lead to hallucinations or delusions. These reactions stem from the overstimulation of the brain and nervous system by excessive THC.
How Long Do Effects Last?
The duration of effects varies depending on the amount of cannabis consumed, its potency (THC concentration), and the method of consumption. When smoked or vaped, effects appear within minutes and can last for 1 to 4 hours. With edibles, the onset is delayed, usually taking 30 minutes to 2 hours for effects to begin. This is because THC must be digested and metabolized by the liver, converting it into a more potent compound. Edible effects can last significantly longer, often 6 to 12 hours.
Individual metabolism, body weight, and tolerance levels also influence how long the effects persist. Those with higher tolerance or faster metabolisms may process cannabinoids more quickly. While acute discomfort usually subsides within these timeframes, some individuals might experience a lingering “hangover” feeling the next day, characterized by residual fogginess or fatigue.
What to Do in the Moment
If you experience a cannabis overdose, recognize that the effects are temporary and will pass. Find a safe, quiet, and comfortable place to sit or lie down to reduce sensory overload. Focus on slow, deep breathing to manage anxiety and rapid heart rate. Stay hydrated by sipping water, but avoid alcohol or other substances. Engaging in calm, distracting activities like listening to music or watching a light show can help redirect focus away from the discomfort.
If you are helping someone experiencing a cannabis overdose, remaining calm and reassuring them is important. Remind them that the feelings are temporary and they are safe. Help them find a comfortable position and offer water. Staying with the person until their symptoms subside provides support and monitoring, especially since judgment can be impaired. Avoiding any form of judgment or criticism is important, as it can escalate their distress.
When to Seek Medical Care
While most cannabis overdose symptoms are not life-threatening and resolve on their own, certain situations warrant immediate medical attention. Call emergency services if the individual experiences severe chest pain, significant difficulty breathing, or a sustained rapid or irregular heart rate. Loss of consciousness, severe vomiting that doesn’t stop, or extreme disorientation are also signs that require urgent medical intervention. If the person expresses suicidal thoughts, or if their paranoia or hallucinations become severe enough to pose a danger to themselves or others, emergency help is necessary.
Medical professionals can provide supportive care, such as sedatives for severe anxiety or breathing support if needed. Individuals with pre-existing heart conditions or mental health disorders should seek medical advice even for milder symptoms, as cannabis can exacerbate these conditions. Any concerning symptoms in children or older adults after cannabis exposure also warrant immediate medical evaluation.