The intoxicating effects of alcohol are caused by the result of its action on the brain. Alcohol produces its depressant action by interfering with the normal functions of the brain. Thus if a person drinks only a small amount of alcohol, the effects may not be obvious.
Higher doses produce more noticeable symptoms.
The acute effects of alcohol wear off as the alcohol is metabolized by the body and the BAL falls to zero. At even higher doses, alcohol causes symptoms of poisoning and even death. There may be false sense of increased confidence and a feeling of well-being. Muscle control and speech are affected. The rate of breathing is decreased, cutting down on the body's oxygen intake.