Most abusive substances fall into one of three general categories: stimulants, depressants, or psychedelics. Alcohol is classified as a depressant. Alcohol produces some of its effects by depressing various brain functions. Alcohol is also a chemical solvent, a local anesthetic, and an irritant. Many of alcohol's side effects are due to these actions rather than to the sedative effect of the agent. Alcohol is found in many different beverages and also in many prescription and nonprescription medications.
Alcohol in low doses causes suppression of inhibitory centers and produces apparent stimulation while impairment of abstract thinking lessens anxiety. At moderate doses, alcohol can cause drowsiness, slowed reflexes and lack of coordination. In large amounts, alcohol decreases vital brain functions, produces sedation, slows the breathing rate, and can cause death.
Alcohol is absorbed from all parts of the gastrointestinal tract. Most of the alcohol enters the bloodstream from the stomach and small intestine. The peak Blood Alcohol Level (BAL) occurs 60 to 90 minutes after ingestion when the stomach is empty. It readily passes from the blood into nearly every tissue in the body, including the brain. The presence of food in the stomach slows the rate of absorption. However the amount of alcohol absorbed remains unchanged.
While no one would get drunk from the alcohol in one or two teaspoons of cough syrup, liver and stomach enzymes cannot deactivate large amounts of alcohol consumed at one time. Alcoholic drinks, including beer cause the amount of alcohol in the blood to rise. Excessive drinking may lead to vomiting and other unpleasant toxic effects. These symptoms are part of the automatic defense systems of the body which are activated to prevent more alcohol from being absorbed. When drinking stops, the liver enzymes will eventually convert excess alcohol into less harmful substances. The final products of alcohol metabolism are carbon dioxide and water.
According to recent news reports, Americans are at risk for a variety of sleep-related health problems. Alcohol use affects sleep in a number of ways and can exacerbate these problems. Because alcohol use is widespread, it is important to understand how this use affects sleep to increase risk for illness. For example, it is popularly believed that a drink before bedtime can aid falling asleep. However, it also can disrupt normal sleep patterns, resulting in increased fatigue and physical stress to the body. Alcohol use can aggravate sleeping disorders, such as sleep apnea; those with such disorders should be cautious about alcohol use.