what causes this ? Fainting Fainting or Syncope is described as the loss of consciousness due to temporary interruption of cerebral oxygenation. It may be due to the interruption of blood flow to the brain. Unconsciousness usually lasts for less than 30 seconds and is accompanied by loss of muscle tone which may result in fall to ground. First patient experiences dizziness, clamminess of the skin, decreased vision, Tinnitus, complete loss of vision, weakness of limbs in the respective manner.