Health Effects

Learn about the health effects of using marijuana. This includes lung health, secondhand smoke, heart health, mental health, and more.


Getting high can impact your decision-making. You might do things that could result in injury. It can also change the way things appear (your perception) and slow your reaction time, which may affect your ability to drive or operate machinery safely.

Smoking and Your Lungs

Smoke hurts your lungs. When you smoke cannabis, you inhale toxins, irritants, and carcinogens like those found in tobacco smoke. Smoking marijuana can lead to a greater risk of bronchitis, cough, and phlegm production. These symptoms generally improve when people quit smoking cannabis.

Secondhand Marijuana Smoke

Secondhand marijuana smoke contains tetrahydrocannabinol (THC) and many of the same toxic compounds found in tobacco smoke. It could affect anyone who breathes it in, especially pregnant women, babies, and children.

Heart Health

Smoking cannabis may increase your blood pressure, can raise your heart rate, or increase the risk of heart attack. If you smoke regularly over the long term, it can cause heart disease.

Brain Development

Babies’ and kids’ brains are still developing, and are more affected by marijuana than adults’ brains. Scientists are still learning about what cannabis does to developing brains, but some studies show cannabis use by mothers during pregnancy may be linked to problems with attention, memory, problem-solving skills, and behavior problems in their children.

The brain does not finish developing until our mid-20s, so using marijuana at a young age can interfere with that. It can affect memory, learning and attention, and make problem-solving more difficult. For more information, see Parent Page.

Mental Health

We still have a lot to learn about whether cannabis use leads to mental health problems or if a mental illness can make a person more likely to use marijuana. As with other drugs, variables like consumers’ age, how early they start, the amount of the drug they use, and their genetics could all impact whether or not long-term problems develop.

Cannabis Use Disorder

Most people do not develop cannabis use disorder, but research shows that some consumers can show signs of problematic use that disrupts important aspects of their lives. They may continue to consume cannabis even when it causes problems with their life, health, work, family, and friends. When some people try to quit, they can have withdrawal symptoms like cravings, trouble sleeping, anxiety, or loss of appetite. Starting to use marijuana at a younger age, or frequent and/or potent use, may put you at greater risk of developing a cannabis use or other substance use disorder.

Safety Tips

Safety Tip

If marijuana becomes a problem, seek treatment.

Visit the Massachusetts Substance Abuse Helpline or call 800-327-5050. The Helpline is the only statewide, public resource for finding substance use treatment and recovery services. Helpline services are free and confidential. Caring, trained Specialists will help you understand the treatment system and your options.

Keep cannabis products locked away, and out of reach of children and pets.

Remember: Getting high could impair your decision-making.

Check in with your doctor if you are using marijuana and are pregnant or planning to become pregnant.

Driving with cannabis in your vehicle? Always keep it in a closed container locked in your glove box or trunk.

Start low and go slow with edibles! They can take one to four hours to take effect.

Always get a ride when using cannabis. Never get behind the wheel.

Only adults 21 or older can purchase, consume, or grow adult-use cannabis.

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