Heartburn or chest pain: When is it heart attack?

You've just eaten a big meal and feel a burning sensation in your chest. Heartburn, right? Probably, but there's a chance the chest pain is a warning sign of a heart attack.

Learning to tell the difference between heartburn and something more serious may be a matter of life and death. Here's what you need to know.

What is heartburn?

Heartburn isn't a disease. It's a symptom. Usually it occurs after eating or while lying down or bending over. You'll notice a burning sensation in your chest that may start in your upper abdomen and radiate all the way to your neck. Heartburn can be brief or continue for a few hours. Sometimes, stomach acid that backs up into the esophagus can leave a sour taste in your mouth — especially when you're lying down.

Normally, digestive acid in your stomach is kept from backing up into your esophagus by the lower esophageal sphincter. This ring of muscle functions as a valve, which opens only as you swallow. But sometimes the valve relaxes or weakens, allowing stomach acid to flow back into your esophagus.

Pressure on the sphincter muscle from excess weight, overeating or lying down too soon after a meal may cause it to open slightly. Certain foods, as well as too much alcohol or caffeine, can relax the sphincter or increase production of stomach acid.

Frequent, persistent heartburn may indicate a more serious condition called acid reflux, gastroesophageal reflux disease, or GERD — the chronic regurgitation of acid from your stomach into your lower esophagus. Long-term GERD can lead to Barrett's esophagus, a condition in which the color and composition of the cells lining the lower esophagus change because of repeated exposure to stomach acid. Barrett's esophagus is a risk factor for esophageal cancer.

Heartburn can also be caused by an inflamed stomach lining (gastritis), a peptic ulcer or a hiatal hernia, when part of the stomach pushes into the chest.

Can other digestive symptoms cause chest pain?

Heartburn isn't the only digestive symptom that can cause chest pain. A muscle spasm in your esophagus may have the same effect. The pain of a gallbladder attack also can spread to your chest. You may notice nausea and an intense, steady ache in the upper middle or upper right abdomen — especially after a fatty meal. The pain may shift to your shoulders, neck or arms.

How would you know if it's your heart?

It can be difficult or even impossible to tell what's causing chest pain. Be on the lookout for these heart-related warning signs:

• Sudden pressure, tightening, squeezing or crushing pain in the center of the chest that lasts more than a few minutes
• Pain spreading to the back, neck, jaw, shoulders or arms — especially the left arm
• Chest discomfort accompanied by shortness of breath, sweating, dizziness or nausea
• Pressure or tightness in the chest during physical activity or when you're under emotional stress

When should you get medical help?

Occasional bouts of heartburn are common. If you have persistent heartburn or take antacids daily, consult your doctor. Your heartburn may be a symptom of GERD or another condition.

If the heartburn seems worse or different from normal — especially if it occurs during physical activity or is accompanied by shortness of breath, sweating, dizziness, nausea or pain radiating into your shoulder and arm — get emergency help immediately. These signs and symptoms may indicate a heart attack. In addition, seek medical attention immediately if you experience new chest discomfort and you have had a heart attack before, have heart disease or diabetes, smoke, are overweight, or have high cholesterol. Proper diagnosis and prompt treatment may save your life.