Is marijuana safe?

• Distorted perceptions
• Impaired coordination
• Difficulty thinking and problem-solving
• Problems with learning and memory
• Respiratory conditions (examples include bronchitis, emphysema, and bronchial asthma)
• Anxiety, depression, and schizophrenia
• Increased heart rate
• Hallucinations, delusions and/or psychosis (when taken in high doses)

• Dizziness
• Red, bloodshot eyes
• Difficulty walking
• Having difficulty remembering things that just happened
• Acting silly for no apparent reason
• Smell of marijuana on hair and clothes

• Irritability
• Sleeplessness
• Decreased appetite
• Anxiety

Marijuana can be laced with substances such as fentanyl, PCP, formaldehyde, or codeine cough syrup without your knowledge. "Blunts" hollowed-out cigars filled with marijuana sometimes have crack cocaine added. These added substances can increase the harm caused by using marijuana.

Is it possible for someone to become addicted to marijuana?

Yes, about one in ten marijuana users will become addicted. For people who begin using younger than 18, that number rises to one in six. For more information, visit the Center for Disease Control (CDC)'s website information on addiction or the National Institute on Drug Abuse's pages on addiction science.

Is it possible to overdose or have a bad reaction to marijuana? 

A fatal overdose is unlikely, but that doesn't mean marijuana is harmless. The signs of using too much marijuana are similar to the typical effects of using marijuana but more severe. These signs may include extreme confusion, anxiety, paranoia, panic, fast heart rate, delusions or hallucinations, increased blood pressure, and severe nausea or vomiting. In some cases, these reactions can lead to unintentional injuries such as a motor vehicle crash, fall, or poisoning.

Synthetic marijuana use increases the chance of fentanyl consumption which can be fatal.

What are the effects of mixing marijuana with alcohol, tobacco or prescription drugs?

Using alcohol and marijuana at the same time is likely to result in greater impairment than when using either one alone. Using marijuana and tobacco at the same time may also lead to increased exposure to harmful chemicals, causing greater risks to the lungs and the cardiovascular system.

Also, be aware that marijuana may change how prescription drugs work. Always talk with your doctor about any medications you are taking or thinking about taking and possible side effects when mixed with other things like marijuana.

Most people who use marijuana do not go on to use other, harder substances. More research is needed to understand if marijuana is a gateway drug a drug that is thought to proceed use of more dangerous drugs (such as cocaine or heroin).

Can secondhand marijuana smoke affect nonsmokers, including children?

Secondhand marijuana smoke contains tetrahydrocannabinol (THC), the chemical responsible for most of marijuana's psychological effects, and many of the same toxic chemicals in smoked tobacco.

Smoked marijuana has many of the same cancer-causing substances as smoked tobacco. However, there are still many unanswered questions about secondhand marijuana smoke exposure and its impact on chronic diseases such as heart disease, cancer and lung diseases.

How does marijuana affect driving?

Marijuana significantly impairs judgment, motor coordination, and reaction time, and studies have found a direct relationship between blood THC concentration and impaired driving ability.

Marijuana is the illicit drug most frequently found in the blood of drivers who have been involved in vehicle crashes, including fatal ones.