First aid is the immediate, temporary care given to a sick or injured person before professional medical help arrives. Its three main objectives, often called the "3 Ps", are:
Preserve life - keep the casualty alive through critical interventions such as CPR or controlling severe bleeding.
Prevent further harm or injury - stop the condition from worsening by stabilising the casualty, immobilising fractures, or removing them from danger.
Promote recovery - apply appropriate treatment (cleaning wounds, positioning the casualty correctly) to support healing.
Preventing further harm or injury is one of these core objectives. A first aider assesses the scene, protects the casualty from additional danger, and takes steps to ensure the injury or illness does not deteriorate while awaiting professional help.
The other options fall outside the scope of first aid. Psychological counselling is a specialised service provided by trained mental health professionals. Curing an illness completely requires medical diagnosis and treatment by qualified healthcare providers. Performing surgery is a complex medical procedure conducted in sterile environments by surgeons, not a first-aid action.