First aid is the assistance given to any person suffering a sudden illness or Injury with care provided to preserve life, prevent the condition from worsening, and/or promote recovery. It includes initial intervention in a serious condition prior to professional medical help being available, such as performing CPR while awaiting an ambulance, as well as the complete treatment of minor conditions, such as applying a plaster to a cut. First aid is generally performed by the layperson  , with many people trained in providing basic levels of first aid, and others willing to do so from acquired knowledge.