Indigestion refers to a condition in which there is discomfort or pain in the upper abdomen, often accompanied by symptoms such as heartburn, nausea, vomiting, and bloating. It occurs when the digestive system does not function properly, causing difficulty in breaking down and absorbing food. Indigestion can be caused by a variety of factors including stress, eating too much or too quickly, consuming excessive amounts of alcohol, smoking, or taking certain medications. In most cases, indigestion is mild and can be managed with over-the-counter antacids or other remedies; however, in some instances it may indicate a more serious underlying condition that requires medical attention.