A new simulation has revealed what happens inside your body when you smoke weed, while a former cannabis user has opened up about his personal struggle with addiction and the changes he experienced after quitting.
According to data from the Office for National Statistics (ONS), around 2.3 million adults between 16 and 59 used cannabis in 2024 — roughly seven percent of that age group. The figures show just how common marijuana use has become, despite its legal status as a controlled substance.
When someone smokes weed, THC travels quickly through the lungs and into the bloodstream before reaching the brain. Over time, frequent use can affect areas linked to focus, memory, and learning, making it harder to stay sharp or retain information.
NIDA director Dr. Nora Volkow explained what makes people so vulnerable to addiction: “There are people [whose genetic susceptibility is] so powerful [that it] can overpower resilient environments, making them liable to addiction.”
To show this process in action, YouTube channel The Infographics Show released a simulation video illustrating how the body reacts to smoking weed over a 30-day period. The visual breakdown highlights both the physical and psychological effects that can build up with regular use.

But the video also points out other effects that come with cannabis use. For instance, the increase in heart rate and dilation of blood vessels explains why many users experience noticeably red eyes after smoking.
Reflecting on his past habits, Dorian admitted: “After being sober for a while, I’m noticing that my anxiety and depression was definitely elevated by smoking weed every day, it wasn’t reduced.”
He went on to describe some of the physical improvements, saying: “Now I don’t feel as winded anymore, I feel like I have way more endurance in my lungs,”
“I feel like I can breathe easier, I don’t wheeze anymore.”
“[You] have more energy and you just have more mental clarity and focus.”
“It’s a lot easier for you to want to set goals and be ambitious and do bigger things when you’re not in that weed brain fog state all the time.”
His story resonated with many viewers who commented that they experienced similar improvements after stopping daily use — from better sleep and sharper focus to more consistent motivation.
Dorian’s experience serves as a reminder that long-term weed use can take a toll on both mental and physical health — but quitting, while difficult, can bring major positive changes over time.