people who drink too much alcohol become "intoxicated." they may become impaired in some or all of their senses like touch or even eyesight. long term drinkers develop tolerance to alcohol. this high tolerance means it takes more alcohol to produce the outward signs of intoxication. intoxication may bring delirium or make people do or say things that are not normal for them. the level of harm done usually depends on the substance and the amount. mild intoxication usually is not permanently harmful. mild stimulants like caffeine usually do not harm the person.