Veteran's Health Library Menu

Health Encyclopedia

Marijuana: Natural = Safe, Right?

Marijuana is readily available to use in many states in the USA. Understanding the possible risks of use is important to ensure the safety of our Veterans.

  • Mental health concerns

  • Overall well-being

  • Physical health

Image of a marijuana leaf with the word marijuana printed underneath.

No matter how you use marijuana (smoke it, eat it, or put it on your skin), it may cause problems with both short term and long-term use.

How marijuana affects your brain

Potential effects from short-term use

  • Poor focus, memory, and reaction time

  • Difficulty with problem-solving

  • Hallucinations, paranoia, and anxiety

Potential effects from long-term use

  • Memory problems and trouble learning new things

  • Depression, hallucinations, paranoia, anxiety, and worsening PTSD symptoms

  • Addiction

Illustration of the brain

It is not safe to drive while on marijuana. It makes it hard to judge distance, concentrate, react quickly to signals and sounds, be alert and coordinated. If alcohol is combined, this risk is even higher.

In regular users, some of the effects from long-term use may last for days or even weeks after stopping marijuana.

How inhaling marijuana affects your lungs 

Inhaling harmful chemicals, such as:

  • Carcinogens (toxins linked to cancer)

  • Gases

  • Small particles

Breathing problems similar to tobacco smokers, such as:

  • Daily cough with mucus

  • Difficulty breathing

  • Lung infections (bronchitis, pneumonia)

Illustration of the lungs

How marijuana affects your heart

  • Increases your risk for heart attack within the first hour of smoking

  • Increases your heart rate 20–100% after smoking and lasts up to 3 hours

  • Changes your heart rhythm; it feels like your heart skips a beat, or is fluttering, or beating too fast or too slow

Illustration of the heart

Is it safe to use marijuana with other medications?

A combination that can be concerning is the use of opioids and/or benzodiazepines with marijuana.

Opioids + benzodiazepines + marijuana:

  • Drowsiness. All three can cause drowsiness.

  • Reaction time. All three can reduce reaction time. Do not drive or operate machinery.

  • Overdose. Opioids and benzodiazepines can cause reduced breathing and in some cases, breathing can stop and a person can die. Marijuana containing higher levels of THC may cause difficulty with thinking and memory and this could result in medication errors where extra doses of opioids, benzodiazepines, or other medications may be taken. 

Example of opioids

Example of benzodiazepines

  • Morphine (MS Contin®, Kadian®)

  • Oxycodone (Percocet®, OxyContin®)

  • Hydrocodone (Vicodin®, Norco®)

  • Fentanyl (Duragesic®)

  • Methadone

  • Heroin

  • Lorazepam (Ativan®)

  • Diazepam (Valium®)

  • Alprazolam (Xanax®)

  • Clonazepam (Klonopin®)

If you have specific questions about the safety of using marijuana with other medications, please contact your provider or pharmacist.

Some marijuana users can become addicted.

  • 30% of daily users can develop problem use.

  • People that start using marijuana before the age of 18 are 4 to 7 times more likely to develop problem use.

  • Problem use can lead to dependence.

  • Dependence can lead to addiction when a person can’t stop using marijuana despite negative consequences.

You can have problems with marijuana withdrawal. Symptoms include: 

  • Anxiety

  • Cravings

  • Irritability

  • Trouble sleeping

You may have withdrawal symptoms the day after you stop using. These can get worse 2 to 3 days after using and can take 1 to 2 weeks or longer to go away.

Recovery and treatment

Contact your VA provider or health care team if you are having concerns about your marijuana use or to learn more about available treatment services.

The marijuana plant is not an FDA-approved medicine:

The U.S. Food and Drug Administration (FDA) has not approved the marijuana plant as a medication due to lack of studies on the risks and benefits. Marijuana contains over 100 chemical substances known as cannabinoids. Some of these, like tetrahydrocannabinol (THC), have mind altering effects and can be intoxicating. Cannabidiol (CBD), another cannabinoid, does not cause the same “high” users of THC experience. THC has been studied for the treatment of several conditions, including nausea and increasing appetite. CBD is similarly being studied for a number of conditions, including childhood epilepsy and inflammation.

What is different between the marijuana product I get from the marijuana shop and a prescription from the pharmacy? 

  • Quality control. Is an edible from one shop the same as another shop? Was the product tested for contaminants? (For example, molds, pesticides.)

  • Product form. What is the difference if I smoke it, eat it or use a cream on my skin? Will they all work?

  • No warnings or reported side effects. Will I get an information sheet from the shop like I do from the pharmacy?

  • No established dose to treat a condition. If I am taking this for pain, how much should I use? 

The right dose of any medicine is important. A specific dose of THC is approved to treat nausea, but high doses of THC may cause vomiting. The ingredients in a medicine must be measured and stay the same from one dose to the next. The marijuana plant contains unknown ingredients that change from plant to plant. This makes it hard to control the “dose” of marijuana needed to treat a condition and use it in the same way we use other medicines. 

Future studies are ongoing to establish the role of the marijuana plant and the cannabinoids found in the plant for treatment of medical conditions. If you have questions about using a marijuana product for a medical condition, please discuss this with your medical provider to determine the most appropriate treatment for you. VA providers are not able to prescribe marijuana products.

Author: StayWell Custom Communications
Last Annual Review Date: 6/1/2017
Help improve the VHL. Share your opinions! Click here for brief survey

VHL Web Tour Video - Opens in a pop up window

Copyright © The StayWell Company, LLC. except where otherwise noted.
Disclaimer - Opens 'Disclaimer' in Dialog Window | Help | About Veterans Health Library