Nighttime heartburn affects four out of five people who suffer regular heartburn and acid reflux. The discomfort and bitter taste can make sleep uncomfortable, even elusive.

While over-the-counter and prescription drugs can treat symptoms once you have heartburn, “the cornerstone of treatment for any disease or disorder is prevention,” say Lawrence J. Cheskin, MD, and Brian E. Lacy, MD, PhD, in their book Healing Heartburn.

Fortunately, sometimes all it takes to prevent nighttime heartburn is a few lifestyle changes. WebMD turned to the heartburn experts to get their tips on stopping nighttime heartburn before it hits — so you can sleep well tonight.

1. Sleep on your left side.This position seems to help reduce nighttime heartburn symptoms, says David A. Johnson, MD, internal medicine division chief at Eastern Virginia School of Medicine, Norfolk, Va. To remember which side to sleep on, Johnson offers this memory trick: Right is wrong.

2. Lose weight, even a little. Heartburn often just gets worse as you gain weight, but losing as little as two and a half pounds can help reduce heartburn symptoms, Johnson says.

3. Sleep with your upper body elevated. When you lay flat in bed, your throat and stomach are basically at the same level, making it easy for stomach acids to flow up your esophagus, causing heartburn. You can elevate your body in two ways:

• Put the head of your bed on 4- to 6-inch blocks.
• Sleep on a wedge-shaped pillow that’s at least 6 to 10 inches thick on one end. Don’t substitute regular pillows; they just raise your head, and not your entire upper body.

4. Wear loose-fitting clothes. Tight clothes, especially near your waist, can put pressure on your stomach, leading to heartburn symptoms.

5. Avoid foods that trigger your heartburn. Foods that trigger heartburn differ from person to person. Common foods and drinks that can cause heartburn and interrupt sleep include alcohol; caffeinated drinks like colas, coffee, and tea; chocolate and cocoa; peppermint; garlic; onions; milk; fatty, spicy, greasy, or fried foods; and acidic foods like citrus or tomato products. Keep a food diary to help you track which foods may trigger your heartburn.

6. Steer clear of late-night meals or big meals. Avoid eating meals two to three hours before bedtime to reduce stomach acid and allow the stomach to partially empty its contents before you sleep, suggests the American Gastroenterological Association. Because large meals put pressure on your stomach, try eating a smaller meal in the evening to help prevent nighttime heartburn symptoms.

7. Relax when you eat. Feeling stressed when you eat in a rush can cause the stomach to produce more stomach acids. Relax after your meal as well — but don’t lay down. Some pros recommend trying relaxation techniques like deep breathing or meditation.

8. Stay upright after eating. This reduces the risk of acid creeping up your esophagus. You’ll also want to avoid bending over or straining to lift heavy objects.

9. Wait to exercise. Allow a couple of hours after a meal before rigorous exercise. This gives your stomach time to empty itself.

10. Chew gum. Chewing gum encourages the production of saliva, which can soothe your esophagus and wash acid down into your stomach. Choose a flavor other than peppermint, which may worsen heartburn in some people.

If lifestyle changes don’t help you manage your heartburn, it may be time for medication or other treatment. Call your doctor if:

• Your heartburn doesn’t go away.
• You have trouble swallowing.
• Your heartburn causes vomiting.
• You still have heartburn after using antacids for two weeks.

Never ignore persistent heartburn. Left untreated, chronic acid reflux can scar and narrow your esophagus, cautions Gary Gitnick, MD, chief of digestive diseases/gastroenterology at UCLA. At its worst, untreated chronic heartburn — a symptom of gastroesophageal reflux disease (GERD) — can develop into esophageal cancer.