Sedatives and tranquilizers are medicines that have a calming effect. Generally, sedatives and tranquilizers depress or slow down certain body functions or the activity of an organ, such as the heart.

Mild sedatives and tranquilizers may be used to reduce anxiety or other nervous system problems, promote sleep, or regulate an organ system. For example, light doses of sedatives can help reduce coughing, nausea, or convulsions. Stronger doses of these substances may be used for severe sleep problems, severe anxiety, symptoms related to psychotic disorders (such as hallucinations or delusions), or as part of anesthesia. These types of sedatives and tranquilizers should only be used as directed by a doctor because they can become habit-forming. Abuse of some stronger substances can lead to severe health problems.