Certain foods - such as chocolate and fatty, or spicy acidic food can cause heartburn.
Easting a large meal or eating too late at night can also bring it on.
Being overweight can put pressure on the valve between the bottom of your gullet and your stomach. This lets acid rise up into our gullet which causes a burning sensation.
During pregnancy, hormones cause the valve at the top of the stomach to relax, which can lead to heartburn.12 The valve allows stomach acid to pass into the gullet and irritate the lining.
Pressure on the stomach may also push contents back up the gullet.
Nicotine from tobacco relaxes the valve between the gullet and stomach.13 This can allow stomach acid and juices, to go back up (reflux)into the gullet which causes heartburn.
Some medicines can trigger or worsen heartburn e.g.14
Excessive alcohol could weaken the valve between the stomach and the gullet and can lead to the backward flow of stomach contents - and that causes heartburn/acid reflux.15
Triggers can include alcohol and caffeinated products, such as coffee.
Stress can reduce the production of substances called prostaglandins which normally protect he stomach from the effects of acid. This could increase your sensitivity to the effects of stomach acid.
Stress can also cause the gastric muscles to contract. This can push the acid contents of the stomach up towards the valve at the top of the stomach. Many people produce more acid when they are anxious and this can cause them to experience heartburn. Tiredness or exhaustion may also cause changes in the body which lead to increased in acid reflux.16
Medicines can affect the unborn baby. Always talk to your doctor or pharmacist before taking any medicine in pregnancy.