Prolonged standing in one position. Sudden changes in posture. Obstruction to the arteries of the neck on turning the head or looking upwards. Poor output of blood from the heart due to various reasons. Symptoms Unconsciousness occurs either suddenly or the casualty may have giddiness for a second, the body crumbles into a heap and soon becomes unconscious.
Face is pale.
Pulse is weak and slow. Breathing becomes less deep than normal. Skin is cold and sticky. Yawning, sometimes sighing, nausea, perspiration, weakness or rapid heartbeats precede the faint. The moment the person feels the faint, get his head down quickly.