What Causes Heartburn at Night?

Did you know nighttime heartburn affects four out of five people who suffer frequent heartburn and acid reflux? This could result from trigger foods, tight clothing pressing on your stomach, or even lying on the right side of your body in bed. It is thought you can minimise your risk of nighttime heartburn by sleeping on your left side, though the reason is not entirely clearX. Heartburn is often accompanied by an acidic or bitter taste in your mouth. This is because heartburn is caused by stomach acid flowing up into the esophagus — the tube that carries food from your mouth to your stomach.

What Causes Heartburn?

Heartburn is a burning sensation behind your breastbone, caused by stomach acid flowing back into the esophagus (also known as acid reflux).¹ Common heartburn triggers include certain foods and drinks, overeating, strenuous exercise, smoking, some medications, pregnancy, being overweight and conditions like hiatal hernia.

Key Takeaways

Heartburn happens when stomach acid flows back into the esophagus, causing a burning sensation in the chest.
Common triggers include certain foods and drinks, overeating, strenuous exercise, smoking, some medications, pregnancy and being overweight.
Simple changes like avoiding trigger foods, eating smaller meals and not eating before bed may help reduce symptoms.
If heartburn happens often or does not improve, talk to your doctor to rule out GERD or another underlying cause.

What Are Common Triggers of Heartburn?

Knowing the common triggers of heartburn can help you make healthy lifestyle choices that lower the risk of triggering a painful heartburn episode. These are the most common triggers of heartburn, but it’s worth noting that triggers can vary by individual.

Certain Foods and Drinks

If you experience heartburn, consider limiting these foods and drinks²:

Spicy food
Citrus foods
Fried or high-fat foods (including healthy fat foods)
Carbonated beverages

Learn more about the foods that may cause heartburn.

Overeating and Eating Too Fast

Overeating can increase the risk of acid reflux by putting too much pressure on the abdomen. Eating too rapidly can also trigger heartburn through acid reflux.³ Break large meals into smaller portions and try to slow down your eating.

Exercise

Strenuous exercise may trigger heartburn in some people, especially workouts that put pressure on the abdomen, such as heavy lifting and stomach crunches.⁴ These exercises can relax the lower esophageal sphincter (LES) muscle, which can lead to food or stomach acid coming back up into the esophagus. These exercises can relax the lower esophageal sphincter (LES) muscle, which can lead to food or stomach acid coming back up into the esophagus.

Medications

Certain medications may contribute to heartburn symptoms in some people.⁵ These can include:

Antidepressants
Over-the-counter pain relief, like ibuprofen
Antibiotics
Statins
GLP-1 medications⁶

Always read the label and consult your doctor before starting new medications if you have heartburn.

Pregnancy

Indigestion and heartburn are common in pregnancy, especially during the second and third trimesters. Heartburn in pregnancy is due to increased hormone levels, which can relax the LES muscle, allowing acid to enter the esophagus. As your pregnancy progresses, your growing baby places increased pressure on your stomach, again raising the risk of heartburn.⁷

Smoking & Nicotine

Nicotine, found in tobacco, may relax the muscles in the lower esophagus, which can allow stomach acid to travel up and cause heartburn.⁸

Belly Fat

Central obesity, also known as belly (visceral) fat, can cause heartburn by exerting pressure on the abdomen.³

Hiatal Hernia

Heartburn is one of the main symptoms of a hiatal hernia. A hiatal hernia is a medical condition where the upper part of the stomach moves above the diaphragm, which results in acid reflux. Many people aren't aware they are suffering from a hiatal hernia.⁹ If you experience frequent heartburn, seek advice from your doctor or healthcare professional.

Sleeping Habits

Certain sleeping habits can cause heartburn at night. Sleeping on your right side can trigger acid reflux, which causes heartburn. This is because the stomach sits above the esophagus when you sleep on your right side, which can cause stomach acid to flow back into the esophagus.¹⁰

Eating too much before bed can also cause heartburn at night because your stomach is still full and actively producing acid when you lie down.³

If you experience heartburn at night, try sleeping on your left side and refraining from eating two to three hours before bed.¹⁰

Eating and Exercise

Did you know everyday habits, such as strenuous exercise and how you eat can lead to heartburn? Workouts that put pressure on the abdomen, such as heavy lifting and stomach crunches, can increase the risk of heartburn as they can relax the lower esophageal sphincter (LES) muscle, which can lead to food or stomach acid coming back up into the esophagus¹. When it comes to diet, overeating can cause your stomach to distend, increasing the chance of acid reflux which causes heartburn. Eating too rapidly can also trigger heartburn², meaning it’s important to chew your food slowly. Not only will your body better digest your meals, but you may suffer from heartburn less too.
Foods That Cause Heartburn

Some types of food can trigger heartburn. Spicy foods, citrus fruits such as oranges and lemons, and fried or high-fat foods have been found to cause heartburn. Even healthier high-fat foods including avocados and cheese pose a risk.³ Try to avoid eating peppermint and chocolate too, as these are also heartburn triggers. Learn more about the foods that cause heartburn.
Heartburn Caused by Drink

Avoiding coffee and caffeinated beverages such as sports energy drinks can help reduce the risk of heartburn. It's best to moderate alcoholic drinks such as beer and wine, which can increase stomach acid levels. Alcohol has also been shown to relax the lower esophageal sphincter (LES) muscle. The LES acts as a barrier between your food pipe (esophagus) and your stomach. By not closing fully after food has entered the stomach, acid can travel up the esophagus, sparking common heartburn symptoms.⁴ Drinking carbonated drinks can also increase heartburn, especially at night.
Medications and Heartburn

Some common medications, including prescription and over-the-counter drugs, can cause heartburn as a side effect.⁵ Always read the label and consult your doctor when starting new medications if you suffer from heartburn.
Heartburn During Pregnancy

Indigestion and heartburn are common in pregnancy, especially during the second and third trimesters. Heartburn in pregnancy is due to increased levels of the hormone progesterone, which cause the LES muscle to relax. As your pregnancy progresses, your growing baby places increased pressure on your stomach, again raising the risk of heartburn.⁶

Find out more about taking TUMS while pregnant.
Lifestyle Causes

Being overweight or smoking can trigger heartburn. Nicotine, a key part of tobacco, is thought to relax the ring of muscle in the lower esophagus that keeps acid in the stomach, where it belongs.⁷ Being overweight can increase the pressure from belly fat on your stomach, leading to heartburn.⁸ Find out more about how your lifestyle can trigger heartburn.
Hiatal Hernia

Heartburn is one of the main symptoms of a hiatal hernia. A hiatal hernia is a medical condition where the upper part of the stomach moves above the diaphragm, which results in acid reflux. Many people aren't aware they are suffering from a hiatal hernia.⁹ If you experience frequent heartburn, seek advice from your doctor or healthcare professional.

How to Help Reduce Heartburn

If you’re experiencing heartburn, try to:

Limit trigger foods and drinks, such as spicy, citrus, fried or high-fat foods and carbonated drinks.²
Eat smaller meals and slow down at mealtimes.³
Avoid large meals before exercise and watch for symptoms during heavy lifting or stomach exercises.⁴
Avoid smoking and nicotine.⁸
For nighttime heartburn, avoid eating two to three hours before bed and try sleeping on your left side.^3,10

An over-the-counter antacid like TUMS can help relieve heartburn symptoms. Talk to your doctor if heartburn symptoms persist or before trying a new heartburn relief product.

Frequently Asked Questions

Can GLP-1 Medications Cause Heartburn?

Yes. Some medications, including GLP-1 medications, may cause heartburn in some people. If you notice symptoms after starting a new medication, talk to your doctor.
Does Exercise Cause Heartburn?

Sometimes. Strenuous exercise may trigger heartburn, especially workouts that put pressure on the abdomen, such as heavy lifting or crunches.
What Causes Heartburn at Night?

Heartburn at night can happen after eating too much before bed or from sleeping in positions that make acid reflux more likely, like your right side.
What Foods Cause Heartburn?

Common food triggers include spicy foods, citrus foods, fried or high-fat foods and carbonated beverages. Triggers can vary from person to person.

Source Citations:

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Exercise Heartburn: Tips When Running, Aerobics, or Other Exercise Triggers Heartburn. WebMD. https://www.webmd.com/heartburn-gerd/features/6-tips-ease-exercise-heartburn. Accessed 05/22/2026.
GERD: Can certain medications make it worse? Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/gerd/expert-answers/heartburn-gerd/faq-20058535. Accessed 05/22/2026.
A Scoping Review of GLP-1 Receptor Agonists: Are They Associated with Increased Gastric Contents, Regurgitation, and Aspiration Events? MDPI. https://www.mdpi.com/2077-0383/13/21/6336. Accessed 05/22/2026.
Gastroesophageal Reflux Disease (GERD) and Heartburn During Pregnancy. WebMD. https://www.webmd.com/heartburn-gerd/heartburn-during-pregnancy. Accessed 05/22/2026.
Does Smoking Tobacco Make Heartburn Worse? WebMD. https://www.webmd.com/heartburn-gerd/features/heartburn-tobacco-connection/. Accessed 05/22/2026.
Hiatal Hernias and Acid Reflux. Healthline. https://www.healthline.com/health/gerd/hiatal-hernia/. Accessed 05/22/2026.
Sleep Positional Therapy for Nocturnal Gastroesophageal Reflux: A Double-Blind, Randomized, Sham-Controlled Trial. Clinical Gastroenterology and Hepatology. https://www.cghjournal.org/article/S1542-3565%2822%2900247-6/fulltext/. Accessed 05/22/2026.