Medically reviewed for current US clinical guidance · Last reviewed: September 21, 2026
The three terms are related but not the same. Acid reflux is the event: stomach acid flowing back up into the esophagus. Heartburn is the symptom: the burning feeling in the chest that reflux can cause. GERD (gastroesophageal reflux disease) is the diagnosis: acid reflux that happens often, usually about twice a week or more, and can irritate or damage the esophagus over time. In short, occasional reflux and heartburn are common, while GERD is the chronic condition.
| Term | What it is | How often | Bottom line |
|---|---|---|---|
| Acid reflux | Stomach acid flows backward into the esophagus | Can happen once in a while to anyone | The event that causes the symptoms |
| Heartburn | A burning feeling in the chest, often after meals or when lying down | Occasional in many people | The most common symptom of reflux |
| GERD | Frequent acid reflux that can damage the esophagus | Usually about twice a week or more, ongoing | The chronic disease; worth seeing a doctor |
Acid Reflux: The Event
A ring of muscle at the bottom of the esophagus (the lower esophageal sphincter) normally keeps stomach contents from flowing backward. When it relaxes or weakens at the wrong time, stomach acid can move up into the esophagus. That backward flow is acid reflux. Almost everyone has it occasionally, often after a large or fatty meal.
Heartburn: The Symptom
Heartburn is the burning feeling in the middle of the chest, sometimes rising toward the throat, that acid reflux commonly causes. It often shows up after eating, in the evening, or when lying down or bending over. Heartburn is a symptom, not a disease, and despite its name it has nothing to do with the heart.
GERD: The Chronic Condition
When acid reflux happens frequently, generally about twice a week or more, or causes bothersome symptoms or damage, it is called GERD. Beyond heartburn, GERD can cause regurgitation, a sour taste, trouble swallowing, chronic cough, or a hoarse voice. Because ongoing acid exposure can injure the esophagus over time, GERD is worth discussing with a doctor.
When to See a Doctor
See a doctor if you have heartburn or reflux more than twice a week, symptoms that do not improve with over-the-counter treatment, trouble or pain with swallowing, unintended weight loss, or vomiting. Seek emergency care for chest pain with shortness of breath, sweating, or pain spreading to the arm or jaw, since these can signal a heart problem rather than heartburn.
Frequently Asked Questions
Is heartburn the same as acid reflux?
No. Acid reflux is stomach acid flowing back into the esophagus. Heartburn is the burning chest feeling that reflux often causes. You can have reflux without much heartburn, and heartburn is one of several possible reflux symptoms.
When does acid reflux become GERD?
Reflux is generally called GERD when it happens frequently, about twice a week or more, or when it causes bothersome symptoms or damage to the esophagus. A doctor makes the diagnosis.
Is GERD dangerous?
Occasional reflux is not harmful for most people, but untreated GERD can irritate or damage the esophagus over time and, in some cases, lead to complications. That is why frequent symptoms should be evaluated.
Can heartburn be mistaken for a heart attack?
Yes, chest discomfort can be confusing. Seek emergency care for chest pain with shortness of breath, sweating, lightheadedness, or pain spreading to the arm or jaw, which can signal a heart problem.
What helps mild reflux and heartburn?
Eating smaller meals, avoiding trigger foods, not lying down right after eating, raising the head of the bed, and maintaining a healthy weight can help. Over-the-counter options exist, but frequent symptoms should be checked by a doctor.
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Sources
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), NIH. Acid reflux (GER and GERD). https://www.niddk.nih.gov/health-information/digestive-diseases/acid-reflux-ger-gerd-adults
- American College of Gastroenterology (ACG). Acid reflux. https://gi.org/topics/acid-reflux/
- NIH MedlinePlus. GERD. https://medlineplus.gov/gerd.html
Medical Disclaimer
This article is for general education and reflects typical US patterns. Frequent or severe symptoms should be evaluated by a doctor, and chest pain with warning signs needs emergency care. This article is not medical advice.