A term used by clinicians and researchers to imply the presence of a SYMPTOM or which require immediate attention as they may indicate serious disease. Common red flags in general practice include: vomiting after a head injury; inability to move a limb and severe pain with a bruise after a fall (this may indicate a fracture); sudden onset of pain which does not respond to paracetamol; sudden shortness of breath or difficulty in breathing; weakness on one side of the face or body; a fever (in an adult) that shows no sign of improving after 5 days; unexplained presence of blood in any fluid arising from any part of the body; and persistent poor appetite with loss of weight. There is a high rate of ‘false positives’ so many patients, even with red flags, turn out not to have serious disease.