Risks of Cannabis Use: What You Need to Know

Cannabis is the most widely used federally illegal drug in the United States, according to the Centers for Disease Control and Prevention (CDC). Tens of millions of Americans use marijuana, the most common form of cannabis.

Many states have legalized cannabis, either fully or for medicinal purposes. However, cannabis use carries short- and long-term health risks.

Here's what you need to know about cannabis health effects.

What Is Cannabis?

Cannabis is a blanket term for products that come from the Cannabis sativa plant. Over 100 cannabinoids, or chemical compounds, make up cannabis.

Marijuana refers to cannabis products with the chemical tetrahydrocannabinol (THC). THC can cause intoxicating side effects, including the "high" people feel when they use marijuana. Another common cannabinoid is cannabidiol (CBD), which doesn't cause intoxication but can have other side effects.

Nearly 62 million Americans ages 12 and older used marijuana in 2023, according to the 2023 National Survey on Drug Use and Health. The total represents over 20% of the population. Nearly 3 million adolescents ages 12 to 17 reported marijuana use, according to the survey.

What Are the Health Effects of Cannabis?

Cannabis use carries short- and long-term health effects that can put you and others at risk.

According to the National Institute on Drug Abuse (NIDA), many factors can affect your specific side effects.

These factors include:

• How much cannabis you consume.
• How you consume it.
• Other drugs you've taken.
• The potency of the product.
• The product's ingredients.
• Whether you have underlying health conditions.
• Your age, sex, and other physical factors.
• Your experience with using cannabis.

What Are the Short-Term Health Risks of Using Cannabis?

Marijuana can cause both physical and mental short-term side effects. Because of the intoxicating effects of THC, your mind and your senses may be altered while the drug is in your system.

You may experience:

• Cognitive effects, such as impairments in memory and attention.
• Feelings of relaxation.
• Increased appetite.
• Increased heart rate and blood pressure.
• Loss of coordination.
• Mental health effects, such as anxiety, fear, and paranoia.
• Mood changes.
• Slower reaction time.

The effects of marijuana on coordination and reaction time can make driving and performing other tasks under the influence extremely dangerous.

Smoking marijuana tends to cause more rapid and potent effects than ingesting marijuana. That's because the chemicals enter your bloodstream more quickly through inhalation. However, both can cause serious, even life-threatening effects. There is a risk of accidental poisoning from edible marijuana among both adults and children.

What side effects can CBD cause?

Although CBD doesn't have the mind-altering properties of THC, it can also cause side effects.

CBD-related side effects include:

• Diarrhea.
• Drowsiness.
• Interactions with other drugs.
• Mood changes.
• Nausea.

What Are the Long-Term Health Risks of Using Cannabis?

Research into the long-term effects of cannabis is still ongoing. However, many studies have reported on the effects of cannabis on the body.

Cannabis and brain health

Long-term cannabis use has been linked to a risk of poor brain development, cognitive decline, and other effects in young people. Because the brain continues to develop until age 25, using substances before that age may be especially harmful to memory, attention, and learning.

A 2022 study in The American Journal of Psychology reported that long-term cannabis users had an average IQ loss of 5.5 points from childhood to midlife. They also experienced declines in learning and processing speed, as well as attention and memory.

Cannabis and heart health

Cannabis use is associated with a higher risk of major adverse cardiovascular events (MACE) such as heart attack and stroke.

A 2025 report in Heart analyzed 24 studies of cardiovascular events and cannabis use. It found that cannabis use carries a higher risk of heart attack, stroke, and cardiovascular-related death. The analysis showed that even younger adults face a higher risk.

A 2024 study in The Journal of the American Heart Association also reported a link between cannabis use and adverse cardiovascular outcomes. The study also reported that heavy cannabis users face an even higher risk.

Cannabis and lung health

Smoking cannabis brings harmful chemicals into the lungs, many of which are also found in cigarette smoke. The difference — cigarettes have nicotine, and cannabis has THC.

Studies have shown an association between smoking cannabis and lung issues. A 2024 review in Respiratory Medicine reported that cannabis smoking is associated with symptoms of chronic bronchitis, such as:

• Coughing.
• Hoarseness.
• Increased sputum (mucus).
• Wheezing.

Cannabis use and pregnancy

According to the American College of Obstetricians and Gynecologists (ACOG), between 2% and 5% of women self-report using marijuana during pregnancy. THC can pass from the mother to the child through the placenta and may also be found in breast milk.

Cannabis use during pregnancy may have an effect on the mother and child. A 2024 study in JAMA Internal Medicine reported that cannabis use was associated with a higher risk of:

• Gestational hypertension (high blood pressure during pregnancy).
• Higher or lower weight gain than recommended.
• Placental abruption.
• Preeclampsia.

Another 2024 study, in Addiction , reported that cannabis use was linked with:

• Lower birth weights.
• Preterm births.
• Neonatal intensive care unit (NICU) admissions.

Some research has linked cannabis use during pregnancy as having an effect on a baby's brain development. However, research is ongoing.

ACOG recommends that pregnant women who use marijuana should stop and discourages cannabis use during lactation and breastfeeding.

Can You Become Addicted to Cannabis?

Yes, it is possible to become addicted to cannabis. According to the Substance Abuse and Mental Health Services Administration (SAMHSA):

• 1 in 6 people who use marijuana before age 18 can develop an addiction.
• 1 in 10 adults who use marijuana can become addicted.

If you have further questions or concerns about cannabis overuse, please talk with your health care provider. They can work with you to decrease or eliminate your consumption.