The after effects of marijuana can vary from person to person, but many of the most common effects are felt by just about all users. Some of the after effects of marijuana will affect the function of the brain, while others may affect one's appetite, energy level, or physical coordination. Many people who smoke or otherwise ingest marijuana report feeling at ease for long periods of time, which can help reduce pain in some people. Allowing too much marijuana into the body can be detrimental to mental health and normal body functioning.
The main chemical that affects a person smoking marijuana is tetrahydrocannabinol, or THC. This chemical can cause after effects of marijuana such as memory loss, altered time perception and sensory perception, and reduced critical thinking skills. Too much THC in the body at once can lead to hallucinations and altered thought patterns, though the levels of THC would need to be fairly elevated. People who ingest marijuana rather than smoking it are more likely to accrue too much THC in the body, leading to some of the more adverse effects of marijuana.
Pain relief is sometimes one of the after effects of marijuana, which is why it is often considered for medical treatments. People suffering from glaucoma often obtain prescriptions for marijuana because the THC can dull the pain receptors and help relax the person suffering from this constantly painful or uncomfortable condition. The drug must be administered by a doctor in carefully controlled doses, however, as marijuana can be addictive both for medical users and recreational users.
Marijuana can also be detrimental to the lungs, throat, and mouth. Inhaling any kind of smoke into the lungs causes the potential for lung damage and can even lead to lung cancer in the long term. This is not exclusive to marijuana smoke, however, and does not apply to marijuana that is ingested.
In many parts of the world, marijuana is an illegal drug, which means legal after effects may occur as well. Possession of marijuana in some parts of the world is an offense punishable by a fine or even jail time. Possession of marijuana with the intent to sell or distribute the drug carries an even harsher penalty, such as protracted jail sentences, hefty fines, and community service requirements. Repeat offenders are likely to incur even more severe penalties.