When you get high, what does the body do to stop you from being high? Get rid of the inhaled chemicals through the liver and kidneys, increased liver and kidney function in the long term leads to liver and kidney disease.
First off, that's not how or why the liver and kidneys work. The liver filters and metabolizes things you've
eaten. Since we're talking about smoked marijuana, the active chemicals diffuse into your blood through the lungs, so the liver isn't involved. Second, kidneys filter out waste from the blood. THC is not considered waste by the body, so it doesn't filter out THC, it just passes through. Sorry.
Chemicals in THC do actually change the chemical structure of your cells, which might make them cancerous.
THC is a singular chemical. So, already your statement is ludicrous. Second, they don't "change the chemical structure of your cells." I think you're thinking of loving chlorine gas. THC and CBD (the two most active chemicals in marijuana) are both benign to cells themselves, they act as an agonist and a neuromodulator respectively.