Heartburn

Did You Know?

• Heartburn is sometimes referred to as indigestion, sour stomach, acid regurgitation, or bitter belching.
• Activities that increase abdominal pressure, such as bending, lifting heavy objects, or certain exercises, can trigger symptoms.
• Studies suggest that stress and lack of sleep may make heartburn feel worse by increasing the body's sensitivity to symptoms.

Pathophysiology

The exact causes of heartburn are not fully understood, but likely involve chemical irritation, pressure on the esophagus, and increased sensitivity to pain. Acid reflux is a common cause, but not the only one; a 1989 study showed that acidic solutions induced heartburn in all participants, while a more basic solution still caused it in over 40%. Ambulatory pH monitoring reveals that only a small percentage of acid reflux episodes trigger heartburn. In GERD, dilated intercellular spaces in the esophageal lining weaken the protective barrier, allowing acid and other substances to reach pain-sensitive nerves. Esophageal reflux can be classified as acidic (pH < 4), weakly acidic (pH 4–7), or weakly alkaline (pH > 7). Without PPIs, about 15% of heartburn cases involve weakly acidic reflux; when taking PPIs, 17–37% of cases are linked to non-acidic, usually weakly acidic, reflux. Bile acid rising into the esophagus can also cause heartburn, though it is slower and less intense than stomach acid exposure. Mechanical stimulation, such as esophageal balloon distension, may trigger heartburn, especially in the upper esophagus, which has more pressure-sensitive receptors.

Diagnostic approach

Diagnostic investigations for heartburn include endoscopy and esophageal pH monitoring. GERD is often diagnosed based on symptoms of heartburn or regurgitation. Endoscopy is used to evaluate people who do not respond to treatment or have alarm symptoms such as persistent vomiting, gastrointestinal bleeding, iron-deficiency anemia, involuntary weight loss, dysphagia, odynophagia, epigastric mass, family history of esophageal or gastric cancer, or new onset of symptoms in those older than 50. Endoscopy can detect erosive esophagitis and Barrett's esophagus, and biopsies can assess for eosinophilic and lymphocytic esophagitis. The esophageal 24-hour pH test or multichannel intraluminal impedance-pH test is often performed in refractory cases. High-resolution esophageal manometry is the standard test for diagnosing esophageal motor disorders and can rule out conditions like achalasia, diffuse esophageal spasm, and jackhammer esophagus. Functional heartburn is diagnosed when a burning sensation persists despite effective acid-suppressing treatment, with no signs of GERD, eosinophilic esophagitis, or major motility disorders, and symptoms must have been present for at least six months, occurring at least twice a week for the past three months.

Treatment

Simple lifestyle shifts—like dropping extra weight and steering clear of heavy, greasy, or spicy meals, especially close to bedtime—can ease heartburn. For mild or occasional symptoms, over-the-counter antacids or alginates offer quick, as-needed relief. Doctors may prescribe a four-week course of PPIs; if that doesn’t help, they might switch to H2 receptor antagonists. Antacids, made from aluminum hydroxide, magnesium hydroxide, or calcium carbonate, neutralize acid fast but only briefly. Alginate, a seaweed extract paired with sodium or potassium bicarbonate, outperforms antacids for heartburn and matches PPIs in short-term GERD treatment. H2RAs curb acid by blocking histamine in the stomach lining, working for four to eight hours; they’re handy for quick relief or as a nighttime add-on to PPIs. For functional heartburn, low-dose tricyclic antidepressants or SSRIs may be tried. As symptoms improve, doctors often taper medication frequency or dose.

History

Heartburn has often been associated with intense emotions, though this was challenged as early as 1591 when the term hartburning described epigastric irritation. Shakespeare referenced heartburn in The Tragedy of Richard the Third. Historical descriptions from the 1500s to the 1700s include phrases such as "a sharpness, soreness of the stomach, heartburning" and "a sharp gnawing pain at the orifice of the stomach." Because the pain was felt in the chest, doctors initially believed it came from the heart, leading to the terms cardialgia or cardialgy. Throughout the 1700s to the 1800s, many terms were used interchangeably, including cardialgia, heartburn, pyrosis, dyspepsia, and indigestion, with little advancement in differentiation until the 1900s.