What Is Marijuana?
Marijuana — also called weed, grass, or pot, among other names — is a mind-altering substance that comes from the cannabis plant. It's one of the most used drugs in the U.S., especially among people aged 18-25. Even so, more research needs to be done to better understand weed's short- and long-term effects.
Cannabis and marijuana aren't the same thing.
Marijuana is a part of the cannabis plant or product that contains tetrahydrocannabinol (THC), which can make you feel high.
Cannabis is anyproduct that comes from the cannabis plant.
What does weed look like?
It looks like dried leaves, flowers, stems, and seeds and can be green, gray, or brown. Its appearance (not smell) might remind you of tobacco.
Weed vs. hemp
By some accounts, one-third of Americans think weed and hemp are the same thing, but they're not. Although they're both from the Cannabis sativa plant, hemp can't get you high. It doesn't contain enough THC.
Hemp is valued for other reasons, though.
For instance, it can be used in:
- Food
- Animal feed
- Clothes
- Sheets and towels
- Biodegradable plastics
- Paper
- Paint
Hemp seed is also rich in vitamins, minerals, fiber, and healthy fatty acids.
Weed vs. cannabidiol (CBD)
After THC, CBD is the second most common substance in cannabis plants. But it doesn’t make you high. CBD can be made into CBD oil and sold as pills, gels, creams, and other forms. Some people use CBD to treat pain and other health issues. For instance, the FDA has already approved a prescription CBD oil as an anti-seizure treatment.
It's also being studied to see if it can help ease a variety of other conditions, including Parkinson's disease and schizophrenia.
But a big concern with CBD products is that the industry isn't regulated. That means that you can't always know exactly what you’re buying. For instance, one study of 84 CBD products found that 18 of them contained THC.
Other cannabinoids
THC and CBD are just two types of cannabinoids in weed. More than 100 other types have also been found. These substances can all react with receptors in your brain that control body functions such as hunger, feelings of pain, and mood.
Weed Strains
If you talk to someone who uses weed often, they'll probably have opinions about the strains they like the most. Or they may say that different types make them feel different ways.
There are at least 1,987 strains of marijuana. In one study, users explained the benefits they felt they got from specific types. For instance, they reported that:
- Blue Dream helped with sleep or posttraumatic stress disorder (PTSD).
- Lemon Skunk improved anxiety and depression.
- Mother of Berries relieved pain.
- Medibud helped with sleep.
Marijuana Extracts
Using heat and different chemicals, marijuana can be transformed into more concentrated forms, such as:
- Hash oil
- Honey, a gooey brown-gold substance
- Wax, with a soft texture like lip balm
- Shatter, which is glass-like and can be easily broken into smaller pieces
These forms, or distillates, can be reheated to create a smoke you can inhale. You might hear this called dabbing.
Extracts like these may contain as much as four times THC as you'd find in regular weed.
Where Do You Get It?
In some states, weed is legal for medical reasons, personal use, or both. If you're an adult, you're allowed to buy it from a licensed source.
Marijuana dispensary
Just like liquor stores are licensed to sell different types of alcohol, cannabis dispensaries have permits to sell weed. They have a variety of strains and types to choose from, and the people who work there can probably suggest products you can try, based on the outcome you're looking for.
How Marijuana Is Used
You can use marijuana in a variety of ways. For instance:
Weed pens
A vape pen can heat cannabis extract that you then inhale.
THC carts
You can buy cartridges of dried, liquid, or concentrated cannabis to vape.
Weed flower
Dried, shredded buds of the plant can be smoked in a rolled cigarette (joint) or hollowed-out cigar (blunt). It can also be put into a pipe or bong (water pipe). Smoking weed is usually the quickest way to feel its effects.
THC-infused drinks
Small amounts of THC can be added to both alcoholic and nonalcoholic drinks.
Edibles
Cannabis can also be put into foods such as brownies, cookies, and candies. Eating or drinking THC takes longer to get you high because it has to travel through your digestive system before getting into your bloodstream. It may take 30 minutes to 2 hours before you feel anything. But edibles may give you a high that lasts much longer (up to 8 hours) than if you smoke or vape weed.
Marijuana Effects
How does cannabis affect you, physically and mentally? Here's what we know.
Marijuana high
The main psychoactive ingredient in weed, THC, travels into your bloodstream to your brain. Once there, it connects to tiny receptors on your nerve cells called cannabinoid receptors. You can think of these receptors like bouncers at a club, monitoring what goes in and out of your cells. They help control various functions, such as hunger, memory, and alertness, and make adjustments in real time to keep your body running smoothly. THC bypasses this system, just like someone slipping past a bouncer at a club.
If you vape or smoke weed, THC could get into your bloodstream quickly enough for you to get your high in seconds or minutes. The THC level usually peaks in about 30 minutes, and its effects may wear off in one to three hours. If you drink THC-infused drinks or eat THC edibles, it may take much longer for you to fully sober up.
Remember, everyone is different. No one can guarantee what your high will feel like, or how long it will last.
Short-term effects
How cannabis affects you depends on lots of factors, including how potent your marijuana is, how you take it, and how much weed you’ve used in the past. Often, it can:
- Make your senses stronger (colors might seem brighter and sounds might seem louder)
- Twist your sense of time
- Decrease your motor skills (which can make driving more dangerous)
- Lower your impulse control
- Make it harder for you to focus, learn, and remember things (which may last 24 hours or longer)
Marijuana side effects
You could also have:
- A dry mouth
- Dizziness
- Upset stomach
- Increased hunger
- Sleepiness
- Hallucinations (see things that aren't there)
- Increased heart rate (which can last a few hours after you stop smoking)
Marijuana Benefits
It appears that weed may help with:
- Ongoing pain
- Stiff muscles or muscle spasms from multiple sclerosis
- Sleep problems for those with fibromyalgia, multiple sclerosis, and sleep apnea
- Anxiety
- Loss of appetite and weight loss in people with AIDS
- Nausea or throwing up from chemotherapy
- Seizures from epilepsy
- Dravet syndrome or Lennox-Gastaut syndrome
Even so, more research needs to be done, especially on marijuana's long-term effects. It doesn't affect all people the same way.
Marijuana Risks and Long-Term Effects
Despite its widespread use, many more studies are needed to understand how regular marijuana use may affect your brain and body.
Can you overdose on marijuana?
According to the CDC, getting "too high" is rarely life-threatening. But large amounts can intensify its effects on you. For instance, you might have:
- High blood pressure
- Racing heart
- Intense hallucinations
- Severe vomiting
- Anxiety or panic attack
- Paranoia
- Not understand where you are or what's going on
If you or someone you know has any of these symptoms after using weed, call a poison control center at 1-800-222-1222. In case of an emergency, always call 911.
Cannabinoid hyperemesis syndrome (CHS)
Regular marijuana use for many years can put you at risk for this condition. It causes intense, uncontrolled bouts of vomiting. Experts aren't sure what causes CHS. One theory is that cannabis use could overactivate the cannabinoid receptors in your brain. So far, treatment options for CHS are limited. Many people find that hot showers and baths can help them control symptoms. Stopping all cannabis use is key.
Marijuana and mental health
Using marijuana may raise your chances of clinical depression or worsen the symptoms of a mental health condition that you already have. Scientists aren’t yet sure why.
In high doses, weed can cause psychosis, which makes you paranoid or causes you to lose track of what's real and what's not. You might hear or see things that aren’t there and can have long-lasting odd thoughts. Psychosis lessens as your high comes down.
Psychosis is a symptom of a serious medical condition called schizophrenia. Schizophrenia also affects the way you understand what's real, but it includes other symptoms, such as trouble with speech and not being able to focus and show emotions. Also, schizophrenia, unlike psychosis, is a long-term condition.
Recent research suggests that if you start to use marijuana at a young age, use it frequently, and for a long period, you could be at risk of having schizophrenia or other mental conditions that involve psychosis. This risk could be higher in young men or people assigned male at birth, especially between 16 and 25 years of age.
Studies also note that if you're at risk of a mental condition, you may be more likely to smoke marijuana at an earlier age, maybe as a way to medicate yourself.
Once you have schizophrenia, stopping marijuana use won't make the condition or its symptoms go away.
If you think you're addicted to marijuana, getting an early diagnosis can help with treatment and prevent the risk of chronic conditions like schizophrenia.
Brain changes
Studies note that early marijuana use can interrupt the normal development of gray matter, a type of brain tissue that helps control mental functions, increasing schizophrenia risks. Early exposure to marijuana is also linked to changes in areas of the brain that are often connected with psychosis.
Using pot heavily, especially in your teen years, may leave more permanent effects. Imaging tests found that some adolescents who used marijuana had fewer connections in parts of the brain linked to alertness, learning, and memory. Tests also show lower IQ scores in some people.
Long-term lung effects
Marijuana smoke can inflame and irritate your lungs. If you use it regularly, you could have the same breathing problems as someone who smokes cigarettes. You may have ongoing coughing with colored mucus, and your lungs may more easily pick up infections. This may be because THC can weaken your immune system.
Heart attack risk
Cannabis makes your heart work harder. Normally, it beats about 50-70 times a minute. But that can jump to 70-120 beats or more per minute for three hours after the effects of THC kick in. The added strain, plus tar and other chemicals that are often present in weed, may raise your chance of having a heart attack or stroke. The risk is greater if you’re older or if you already have heart problems.
Periodontal (gum) disease
Smoking and vaping tobacco can cause bacteria to grow underneath your gums, which can lead to this condition. Frequent marijuana use causes the same negative effects. Periodontal disease doesn't just cause tooth loss but has also been linked to many other health issues, including heart disease and preterm labor.
Marijuana and fertility
If you or your partner are trying to have a baby, doctors suggest that you both stop using marijuana. Some research suggests that it could affect both male and female fertility, but much more research needs to be done.
Marijuana and cancer
Regular use may raise your risk of cancers in your lungs, head, and neck, but more research is needed. Limited evidence suggests that heavy cannabis use may lead to one type of testicular cancer. And there's not yet enough information on whether it may lead to other cancers, including:
- Prostate
- Cervical
- Bladder
- Non-Hodgkin's lymphoma
Marijuana Safety
To use cannabis wisely:
Buy it from a legal source. No federal standards exist for the cannabis industry, but you have a better chance of knowing what you're getting if you buy from a dispensary instead of off the street (which is still illegal).
Don't mix it with alcohol. More than 1 in 10 drinkers say they've used marijuana in the past year. Combining alcohol and marijuana at the same time roughly doubles your odds of drunk driving or legal, professional, or personal issues.
Protect your lungs. Instead of smoking, try another form, such as edibles or a tincture you put under your tongue. If you do smoke, don't hold it in your lungs for more than a second. It's a myth that the longer you hold it in your lungs, the higher you'll get.
Time your high. Don't use weed within four hours of driving and 24 hours of working, especially if your job requires you to follow safety guidelines. Always stay sober when it's important for you to be alert — for instance, when you're around kids, caring for an aged or sick loved one, or you might get called into work.
Keep all cannabis away from kids. Especially THC-infused sodas and gummies that might be mistaken for treats. Make sure your pets can't get into your stash either.
Marijuana Addiction
About 1 in 10 people who use marijuana get addicted or have cannabis use disorder. This means you can’t stop using it even if it harms your relationships, school, job, health, or finances. The CDC states that you have a 10% risk of a cannabis use disorder if you use marijuana.
Like the possible risk of chronic conditions such as schizophrenia, the chances of cannabis use disorder are greater the younger you start marijuana and the more heavily you use it. For instance, the odds of addiction are 1 in 6 if you use marijuana in your teens. It might be as high as 1 in 2 among those who use it every day.
You might have cannabis use disorder if you:
- Crave weed
- Try to quit cannabis but just can't
- Spend a lot of your time using cannabis
- Use more marijuana than you had planned to
- Miss out on time with family or friends to use pot
- Still use marijuana even though it causes you physical or mental problems
- Use it while you drive or during other high-risk activities
- Need more weed to get the same high
- Have issues with learning, attention, or memory
Weed withdrawal
You can also grow physically dependent on marijuana without getting addicted to it. If you stop using it, you might feel:
- Easily irritated
- Aggressive
- Restless
- Depressed
- Anxious
- Unable to sleep
- Uninterested in eating
Although they're not as common, you could also have physical symptoms, such as:
- Sweating
- Shaking
- Upset stomach or vomiting
- Stomach pain
- Headache
How to get help
If you've been regularly using large amounts of weed, withdrawal symptoms might start within a day or two. By day 3, the worst is usually over. But some people have symptoms that linger for a few weeks.
Most people don't need medical care (detox) to stop using marijuana regularly. But you may benefit from professional help if you have:
- A mental health issue
- Cannabis use disorder
- Other substances you're also trying to quit
- An ongoing health issue that's getting worse
Talk to your doctor if you have questions about how to stop using marijuana or your symptoms. There are a lot of myths out there about weed addiction. Only you can decide if you're ready to get help.
Do You Need to Tell Your Doctor If You Smoke Weed?
It's important that your doctor knows about cannabis and any other drug you use. It will become part of your medical record, but that's private information. Your doctor shouldn't judge you for it. And they're not legally obligated to tell the police. Their job is to help you get healthy.
Marijuana and anesthesia
Whether you use weed recreationally or medically, it can affect how your anesthesia works. If your doctor is aware of your use, they'll be able to take the steps to make sure you stay sedated, or "asleep," for the entire surgery. If you use marijuana at least once a week, you might need more anesthesia.
The American Society of Regional Anesthesia and Pain Medicine issued guidelines in 2023 for information to share with your doctors before any surgery. They include sharing:
- Whether you use pot
- How often you use it
- How much you use
- What type you use
- How recently you used it
If you used it recently, your doctor might reschedule your surgery if it's elective (optional) and not an emergency. This is the case even if you don't use marijuana a lot.
Extra risks involved with surgery when you use weed include:
Your stomach contents coming into your throat. If you recently used or regularly use marijuana, your stomach may take longer to empty. That puts you at risk of your stomach contents coming back up and being sucked into your lungs.
Having a heart attack. If you already have heart disease, using marijuana within 60 minutes of getting anesthesia further increases your risk of a heart attack.
Added risk if you need more anesthesia. If you need more anesthesia to fall asleep because of your pot use, you're at a higher risk of low blood pressure and a delayed wake-up after surgery.
Breathing issues. Regular cannabis use can lead to coughing, wheezing, phlegm, and a higher risk of respiratory infections. This may cause your airways to be more sensitive, which could cause problems when your doctor puts in or takes out your breathing tube. Along with having trouble breathing, you might feel like you're having an asthma attack or have less oxygen in your lungs.
Complications after surgery. Regular marijuana use may cause you to have more pain after surgery. This could cause you to rely more on opioids to ease the pain. If you use these drugs more, you're at risk for opioid use disorder.
No matter how often you use marijuana, avoid all forms of it on the day of your surgery. If you don't, or your surgery is unplanned, you risk life-threatening complications:
- If you use cannabis on the day of surgery, it can increase your heart rate and lower your blood pressure. This can lead to a heart attack.
- If you take edibles on the day of your procedure, it could cause aspiration pneumonia, which happens if you inhale food into your lungs. This can be fatal.
Other reasons to tell your doctor
Not just your surgeon or primary care doctor, but any health care provider you see for physical or mental health, needs to know about your cannabis use. That's because marijuana can affect major organs such as your heart and lungs. It can also affect your emotional state. And your baby's health, if you're pregnant or nursing.
Even your dentist should know if you sometimes get high. That way, they can monitor you more closely for complications such as gum disease and head and neck cancer, which are linked to cannabis use.
Marijuana During Pregnancy
Using weed in any form when you're pregnant is unsafe for your growing baby. It raises their risk of:
- Premature birth
- Low birth weight
- Abnormal brain development
- Being hospitalized after birth
- Death within one year of birth
Although more research needs to be done, some studies suggest that using cannabis while you're pregnant can affect your kids later in life. It's been linked to issues with:
- Problem-solving
- Attention
- Memory
- Behavior
Is it safe to nurse and use marijuana?
The short answer is no. The substances in weed will be passed on to your baby and may harm them. "Pumping and dumping" isn't a solution. Chemicals such as THC stay in your body fat and are released slowly over time. That means your baby could be exposed to them after you stop using weed.
Is it safe to use CBD during pregnancy?
Researchers still don't know how CBD could harm a developing baby. So, you should stop using all CBD products while you're pregnant and nursing.
If you have questions, talk to your doctor.
Marijuana Legalization
Right now, medical marijuana is legal in 39 states, while recreational cannabis is legal in 24 states and Washington, D.C.
States where weed is legal
Cannabis laws differ from state to state. Use a legitimate source — for instance, your state's Office of Cannabis Management or Cannabis Commission — to find out the laws where you live.
Driving while high
It's not only dangerous but against the law to drive after using cannabis. That's because when it's in your system, THC can:
- Slow your reaction time
- Disturb your coordination
- Make it hard for you to gauge distances
If you use weed and need to go somewhere, ask a sober friend to drive you, take public transit, or call a taxi or ride-share service.
Takeaways
Marijuana is one of the most used drugs in the U.S. How it affects you will depend on a lot of different factors, including your age, the amount and type you use, and any other medications or drugs you take. More research about weed's benefits and risks is needed. But so far, it's clear that you should avoid all forms of it, including CBD products, if you're pregnant, trying to get pregnant, or nursing.
Marijuana FAQs
What was marijuana originally used for?
Cannabis use dates back to 2800 B.C. There's evidence that it was used in Central Asia and Western China to treat health issues such as arthritis, asthma, pain, and depression.
