Alcohol belongs to a class of drugs known as 'depressants' because they slow down parts of the brain, such as judgement, reaction time, and motor skills. It also slows down the nervous system, lowering the heart rate and slowing breathing respirations.
Alcohol is a legal drug (for people 21 and over in the United States and 18 and over in parts of Australia and Canada) and is most commonly used. If taken in moderation alcohol does not harm most people. However, regular excessive drinking of alcohol can cause a variety of health, personal, and social problems.
Alcohol passes straight into the bloodstream from the small intestine and stomach. Immediate effects include feeling relaxed and less inhibited, followed by reduced concentration, slurred speech, and blurred vision. Alcohol also effects coordination and judgement. It can bring on moodswings, agression, and sadness more easily than usual. People who are drunk are more likely to become hostile and violent during an argument than they would while not under the influence of alcohol.
The amount of alcohol in the bloodstream is called the blood alcohol concentration or BAC. Blood alcohol concentration is determined by how much alcohol a person drinks and over what period of time.
Some people's blood alcohol concentration will be higher after drinking the same amount as other people. There are a number of reasons for this including: drinking on an empty stomach, if the person is of small build, or if they are overweight and in poor health.
Some physical problems commonly associated with regular alcohol use are liver damage, heart and blood disorders, stomach inflammation, brain damage, impotence in men, and irregular periods in women.
Regular heavy drinkers also commonly experience intense emotional problems including depression, relationship and family problems, lack of motivation, and poor work performance. Financial difficulties and legal problems are also commonly experienced among heavy users.
People who regularly drink can also develop tolerance, which means they need to drink more and more to experience the same effects as before. Regular drinkers are at risk of becoming dependent on alcohol. If alcohol is unavailable they may panic or feel anxious. Withdrawl occurs when a person who's dependent on alcohol stops using or severely cuts down the amount they drink. Withdrawl symptoms include sweating, tremors, vomiting, convulsions, and hallucinations.
Combining alcohol with other drugs can be dangerous and even deadly. Mixing over-the-counter or prescribed medications with alcohol can reduce their effectiveness or cause an allergic-type reaction. Mixing alcohol with minor tranquilizers or marijuana impairs judgement and coordination even more, and can cause respiration or heart failure.