Therefore, any use can lead to addiction. Once having tried cocaine, an individual may have difficulty predicting or controlling the extent to which he or she will continue to use the drug. Use of cocaine in a binge, during which the drug is taken repeatedly and at increasingly high doses, leads to a state of increasing irritability, restlessness, and paranoia. This may result in a full-blown paranoid psychosis, in which the individual loses touch with reality and experiences auditory hallucinations. Regularly snorting cocaine, for example, can lead to loss of sense of smell, nosebleeds, problems with swallowing, hoarseness, and an overall irritation of the nasal septum, which can lead to a chronically inflamed, runny nose.
Ingested cocaine can cause severe bowel gangrene, due to reduced blood flow.
Intravenous cocaine users may also experience an allergic reaction, either to the drug, or to some additive in street cocaine, which can result, in severe cases, in death. Because cocaine has a tendency to decrease food intake, many chronic cocaine users lose their appetites and can experience significant weight loss and malnourishment. The MTF assesses the extent of drug use among adolescents and young adults across the country. The proportion of high school seniors who have used cocaine at least once in their lifetimes has increased from a low of 5.9 percent in 1994 to 9.8 percent in 1999. However, this is lower than its peak of 17.3 percent in 1985.