If you've had heartburn or acid reflux for so long that you have trouble swallowing, then it's a sign that damage to the esophagus has been building for awhile. The esophagus may be inflamed, scarred or full of ulcers, indicating esophageal cancer. Other symptoms to be on the look out for include nausea and vomiting, particularly if you're vomiting blood.
It's important to note that children can suffer from heartburn and acid reflux as well. Unless you have an extremely advanced child, he or she probably won't be able to put the discomfort into words, so take note if a baby experiences trouble swallowing. Other signs of gastroesophageal reflux disease in children are repeated regurgitation, asthmalike symptoms, frequent arching of the back and irritability after feedings. The good news? Many infants and children outgrow the condition, though don't sit around and wait for them to do so: See a doctor.