The constriction of a passage or tube in the body that blocks the blood flowing to and from it, and thus disturbs the working of the affected organ. It is usually caused by compression or twisting. Strangulation customarily occurs when part of the INTESTINE herniates either inside the abdomen or outside as in an inguinal HERNIA. If a section of the intestine twists, this may strangulate and is known as a VOLVULUS.

Strangulation of a person's neck, either with a ligature or with the hands, obstructs the jugular veins in the neck, preventing the normal outflow of blood from the brain and head. The TRACHEA is also compressed, cutting off the supply of air to the lungs. The combination of these effects leads to HYPOXIA and damage to the brain. If not quickly relieved, unconsciousness and death follow. Strangulation may be deliberate or accidental – the latter being a particular hazard for children, for example, when playing with a rope. Removal of the constriction, artificial respiration, and medical attention are urgently necessary.