It comes down to gravity. During the day, staying upright helps keep stomach contents where they belong, but lying down removes that advantage, which is why heartburn, chest discomfort, a sour taste, coughing, and throat irritation can feel more pronounced once the day’s routines give way to rest.

Understanding Acid Reflux and Nighttime Symptoms

Acid reflux happens when stomach contents move upward into the esophagus. While this can occur at any time, the effects are often more noticeable overnight, since the body’s usual upright defenses against reflux aren’t in play while sleeping.

How Sleep Position Affects Reflux

Sleeping position appears to influence how easily stomach contents can travel back into the esophagus. Some positions seem to make it harder for acid to move upward, while others may make reflux more likely in people who are already prone to it.