Caffeine

The chemical compound is derived from plants. Caffeine most often consumed in beverages, such as coffee, tea, soft drinks and energy drinks. It may also be found in powder or pill form.

Caffeine is widely used to improve alertness and elevate moods. Certain pain relievers contain caffeine, as the compound has been shown to increase drug effectiveness and help the body absorb the pain relieving drug more quickly.

Caffeine is a diuretic, meaning it increases the need to urinate. It also temporarily increases alertness and, when taken near bed-time, may disrupt sleep patterns. When taken in large doses, caffeine can cause nervousness, jitteriness and tension.

Caffeine intake during pregnancy is linked to an increased risk of miscarriage.

Caffeine is addictive. Tolerance and dependence may develop after prolonged caffeine use. This reduces the chemical compound's perceived stimulant effects. To temporarily overcome the body’s tolerance to the substance, caffeine must be consumed in increasingly larger doses. When caffeine consumption is halted, it can lead to a "crash", including irritability, anxiety, loss of concentration and other withdrawal symptoms.

An acute overdose of caffeine can cause caffeine intoxication. This condition is similar to overdose from other stimulants. In extreme cases, psychosis and death may occur.