How do i know exactly what is reflux and what are the symptoms?

Heartburn: Gastroesophageal reflux disease is the movement of acid-containing gastric juices from the stomach back into the esophagus or occasionally as high as the mouth, trachea or sinuses. The classic symptom is heartburn due to esophageal irritation by acid. Regurgitation, sore throat, sinusitis, laryngitis and pneumonitis sometimes occur. Causes include hiatal hernia and defective sphincter mechanisms.