Overview
Cannabis comes from the Cannabis plant and may be smoked, vaped, eaten, or used in other forms. Its effects depend on the product, how much is used, how it is used, and the person's age, health, and past experience. Cannabis can impair memory, coordination, judgment, and reaction time, which can affect daily activities and safety.
Key Symptoms
Short-term effects can include feeling relaxed, changes in mood, altered sense of time, trouble concentrating, red eyes, dry mouth, and increased appetite. Some people have unpleasant effects such as anxiety, panic, paranoia, dizziness, nausea, or confusion. Problematic use over time can involve cravings, difficulty cutting down, using more than intended, and problems at school, work, or home.
Causes and Risk Factors
Cannabis affects the brain through compounds such as THC, which can alter thinking, mood, and perception. Risk of harm is higher with frequent use, high-THC products, starting use at a younger age, and using cannabis together with alcohol or other drugs. People with a personal or family history of mental health conditions may be more likely to have serious psychological effects.
Who Is Affected
People of all ages may use cannabis, but adolescents and young adults are especially vulnerable to harms because the brain is still developing. Pregnant people, people who drive or operate machinery, and people with heart, lung, or mental health conditions may face added risks. Cannabis products can also harm children if they are accidentally eaten, especially edibles.
Prevention
Prevention includes delaying or avoiding use, learning about local laws and product risks, and keeping cannabis locked away from children and pets. Do not drive, cycle, or use machinery after using cannabis. Avoid combining cannabis with alcohol or other substances, because this can increase impairment and other harms.
Diagnosis and Tests
A healthcare professional may ask about the type of cannabis used, frequency, reasons for use, symptoms, and effects on work, school, relationships, and safety. They may also ask about mental health, other substance use, and any physical symptoms. Drug tests can detect cannabis exposure, but they do not by themselves show current impairment or a substance use disorder.
Treatment Categories
Treatment for cannabis-related problems may include counseling, behavioral therapies, support groups, and care for anxiety, sleep problems, or other related issues. A clinician may screen for cannabis use disorder and coexisting mental health or substance use conditions. If someone is using cannabis for medical reasons, any changes should be discussed with a qualified healthcare professional.
Living With It
If cannabis use is causing problems, it can help to track triggers, set goals, and seek support from a healthcare professional, counselor, or trusted support person. Recovery may involve reducing use, stopping use, and building other ways to manage stress, sleep, or pain. Relapse can happen and is a reason to seek more support, not a reason to give up.
When to Seek Medical Care
Seek medical care if cannabis use is affecting your mental health, memory, school or work, relationships, or ability to stop. It is also important to get help for repeated vomiting, chest symptoms, severe anxiety, or suspected use during pregnancy. Ask for urgent assessment if a child may have eaten a cannabis product.
When It May Be an Emergency
Get emergency help right away for trouble breathing, seizures, severe confusion, loss of consciousness, chest pain, or violent or highly agitated behavior after cannabis use. Emergency care is also needed if someone has signs of psychosis, such as hallucinations, extreme paranoia, or being unable to tell what is real. Children with suspected cannabis poisoning need urgent medical attention.