crazy mood swings, impulsiveness, derangement, rage, dependence, agitation, assault. meth makes your body heat rise, causing respiratory or heart problems. meth causes you to hallucinate, or feel things that aren’t really here. examples are feeling bugs crawling on you, hearing things, seeing things that aren’t really there. when meth users feel the imaginary bugs crawling on them, they pick at their skin which leaves them with open sores. using meth messes with your teeth also. it can lead to rotten teeth from poor hygiene, grinding, and just from the acidity of the drug. meth speeds your heart which can cause a heart attack or stroke. meth makes you lose your appetite, which can make you thinner from lack of food, which can make your muscles and tissue basically tear away. it also causes muscle spasms and unwanted twitching. excessive plucking and the chemicals in the drug can cause your hair to fall out. meth destroys your immune system which can lead to slow healing, gray skin, acne and open sores. not only does it mess with your body, it messes with your brain. meth kills brain cells and makes you have slower reactions and responses to things.