Cocaine is a product of the coca plant and is an illegal recreational drug. It is not a narcotic (a drug which causes drowsiness and sleep, typically heroin or other opiates) although it is referred to as one by the legal system. Cocaine is a strong stimulant, which produces increased activity of the central nervous system (associated with the brain and spinal cord) and the peripheral nervous system (the nerves that stem from the spinal cord).

Cocaine can be taken into the body by several methods and in several forms. Powdered cocaine (hydrochloride) can be snorted, injected, eaten or applied to other mucus membranes such as the vagina or rectum. The "freebase" form (often called crack) can be used by smoking . The amount of cocaine required to produce an effect varies with the individual, with the purity of the drug, and with the means of taking it into the body. A smaller amount is usually required with injection into a vein or with smoking.

Cocaine use can cause a number of medical problems -- including cardiovascular (heart and blood vessels) collapse, irregular heartbeats, heart attack, lung damage from smoking, damage to veins and transmission of blood-borne diseases due to injecting using dirty needles, damage to a fetus, and very high temperature elevations (hyperthermia). Cocaine also causes mood swings, delirium, migraine-type headaches, seizures, transient ischemic attacks (TIA), and strokes. Although it does not produce the dramatic withdrawal symptoms seen in heroin addiction, cocaine is extremely addictive and users who stop may experience severe drug craving, depression, and lethargy.

Stroke secondary to cocaine probably occurs because cocaine causes blood vessels to narrow (constrict) while also increasing blood pressure (hypertension). This vasoconstriction can be severe enough to reduce or block blood flow through the arteries in the brain.

Stroke secondary to cocaine is most common in men under 40 years old. Risks include a history of recent cocaine use. In a few people who experience stroke after using cocaine, an underlying arteriovenous malformation is found, which may have predisposed them to developing a stroke. In these cases the stroke is due to bleeding in the brain as opposed to decreased blood flow.