The prolonged use and subsequent abuse of legal and illegal substances can have profound and often irreparable effects on the body. Continued abuse and an inability to stop can lead to years of exposure to a substance and possible negative effects on the body. A number of factors influence the severity of damage such as the age when the substance was first used, frequency of use, quantity of use and a person's general health.
Alcohol
The National Institute on Alcohol Abuse and Alcoholism reports alcohol abuse can have long-term effects. Some effects include blackouts and memory lapses, thiamine deficiency, brain damage and certain types of cancer, especially of the esophagus, pharynx and mouth. Thiamine is an essential nutrient required by all the tissues in the body. A deficiency can occur when there is an insufficient intake of this key nutrient due to a poor diet, as is often seen with alcoholism. Cirrhosis of the liver is often an occurrence that, if continued, can lead to a potentially fatal disorder known as hepatic encephalopathy. In utero, alcohol abuse can lead to Fetal Alcohol Syndrome (FAS), which can affect a developing fetus. FAS can lead to physical deformities in a baby or heart defects, learning disabilities and mental retardation.
Cocaine
Cocaine is a highly addictive drug, delivering its desired effects on the drug user almost immediately. Serious complications can include severe headaches, seizures, heart attack, stroke, coma or death. Long-term physical effects of cocaine abuse depend on the method of use but can include loss of smell, hoarseness, perforation of the nasal septum, pulmonary edema, chronic bronchitis and complications of the bowel. Chronic users often lose significant amounts of weight and can become malnourished. Other effects may include psychological problems such as hallucinations and paranoia.
Marijuana
Marijuana is the most commonly abused drug, according to the National Institute on Drug Abuse (NIDA). Long-term effects of prolonged marijuana abuse may be a decrease in testosterone levels that can affect fertility, increased heart rates, chronic bronchitis, emphysema, cancer and damage to the immune system. Marijuana has been found to have 50 percent to 70 percent more carcinogens than tobacco, the NIDA says. Increased heart rates may subsequently lead to higher risk of heart attack and stroke. Other problems may occur such as memory impairments, learning problems and cognitive defects. Prolonged use of marijuana has also been linked to higher incidences of schizophrenia among young users.
Other Drugs
Some other commonly abused drugs are sedatives and barbiturates (Valium, Quaaludes), hallucinogens (LSD), heroin, methamphetamines and MDMA (ecstasy). According to the NIDA, long-term health effects from these drugs vary but can include increased heart rate and blood pressure, hepatitis and damage to the lungs, liver, kidneys and brain. Some abusers display signs of psychosis such as paranoia, delusions, violent behavior and suicidal thoughts. Fatalities often occur from mixing and using several substances together.
