How does cannabis affect your health?
Cannabis affects health through two main compounds. Delta-9 THC causes a high and drives most of the physical and mental effects. CBD does not cause a high, but it can change how your body processes certain medications. The size of the effect depends on the dose, the product's THC level, the route of use, how often you use it, your age, and your medical history. Short-term effects arrive within minutes when you smoke or vape and within 30 to 90 minutes when you eat an edible.
Is Cannabis Bad for You? Health Risks, Facts, and How CBD Differs
Heart rate and blood pressure
THC can push resting heart rate up by 20 to 50 beats per minute for up to three hours after use. Blood pressure may fall when you stand, which brings dizziness or fainting. For someone with narrowed arteries or an arrhythmia, that extra workload can trigger chest pain or a cardiac event. Heavy long-term use is tied to a higher risk of heart rhythm problems.
can cannabis use harm your health
Lungs and airways
Smoked cannabis delivers tar, irritants, and carbon monoxide. Regular smokers report more cough, phlegm, and wheeze, and long-term use is linked to chronic bronchitis. Vaping THC products cut with vitamin E acetate caused a nationwide outbreak of severe lung injury known as EVALI. No heating method is risk-free for the airways.
can cannabis use harm your health
Brain, memory, and mood
THC binds to cannabinoid receptors in brain regions that control memory, attention, coordination, and reward. Short-term effects include slower reaction time, trouble holding new information, and impaired driving. High doses can set off anxiety, panic, or paranoia. Use that starts in the teen years is tied to lasting problems with attention and learning. Heavy use raises the odds of psychosis in people with a family history of psychotic disorders.
Dependence and withdrawal
About 3 in 10 people who use cannabis develop cannabis use disorder, and the risk climbs when use starts before age 18. Withdrawal brings irritability, insomnia, low appetite, and cravings. Symptoms peak in the first week after stopping and can last two weeks or more.
Appetite, nausea, and pain
THC can ease chemotherapy-induced nausea and increase appetite. Prescription cannabinoid medicines exist for those uses. Evidence on chronic pain is mixed. Some users get relief, while others get side effects such as sedation and dizziness with little benefit.
CBD-specific effects
CBD does not intoxicate. The FDA has approved one CBD medicine for severe childhood epilepsies, but evidence for anxiety, sleep, and pain outside that use is still early. CBD blocks cytochrome P450 enzymes, so it can raise blood levels of blood thinners, seizure medicines, and immunosuppressants. High daily doses have been linked to liver enzyme changes, and the FDA advises liver monitoring for some patients.
People who should take extra care
- Anyone under 25, while the brain is still developing
- People who are pregnant or breastfeeding
- People with heart disease, arrhythmia, or a personal or family history of psychosis
- People on prescription drugs, such as blood thinners
- Drivers and workers in safety-sensitive jobs
Steps to lower your risk
- Check your state law and read the product's lab report before you buy.
- Start with a low dose and wait at least two hours before taking more, longer for edibles.
- Pick products with a stated THC and CBD content so you know the dose.
- Skip smoking and vaping, and choose oral or topical forms to spare your lungs.
- Avoid cannabis before driving or using machinery.
- Tell your doctor and pharmacist about every cannabis or CBD product you use.