THC moves from your lungs into your bloodstream and throughout your body. Within minutes, your heart rate may increase by 20 to 50 beats per minute according to researchers. That rapid heartbeat can continue for up to three hours. For people with heart disease, this faster heartbeat could raise the risk of heart attack.
One of the telltale signs of recent marijuana use is bloodshot eyes. They look red because marijuana causes blood vessels in the eyes to expand or dilate. Marijuana may help stop the growth of blood vessels that feed cancerous tumors.
Central Nervous System
When you inhale marijuana smoke into your lungs, it doesn’t take long for THC to enter your bloodstream. From there, it is quickly transported to your brain and the rest of your organs. When you get marijuana from food or drink, it is absorbed a little more slowly.
THC triggers your brain to release large amounts of dopamine, a naturally occurring “feel good” chemical. That’s what gives you a pleasant “high.” It may heighten your sensory perception, as well as your perception of time. THC changes the way you process information, so your judgment may be impaired. It may also be difficult to form new memories when you’re high.
Changes also take place in the cerebellum and basal ganglia, upsetting your balance, coordination, and
reflex response. All those changes mean that it’s not safe to drive. Very large doses of marijuana or high concentrations of THC can cause hallucinations or delusions.
According to researchers, there may be an association between marijuana use and some mental health problems like depression and anxiety but more research is needed to understand the connection. In people who have schizophrenia, marijuana use can make symptoms worse.
When you come down from the high, you may be tired or feel a bit depressed. In some people, marijuana can cause anxiety. About nine percent of marijuana users develop an addiction, according to researchers. Symptoms of withdrawal may include irritability, insomnia, and loss of appetite.