Heartburn is a burning pain in the chest, just behind your breastbone. The pain is caused by stomach acid travelling up towards the throat (acid reflux). Hearburn often gets worse after eating, especially in the evening, or when lying down or bending over.
Heartburn has no obvious cause, but some of the factors that may influence it are foods (such as coffee, tomatoes, alcohol, chocolate, and fatty or spicy foods), being overweight, smoking, pregnancy, stress, anxiety, stomach ulcer, and bacterial infection in the stomach.