Dry heaves, or retching, is a common symptom where the body undergoes the physical motions of vomiting without expelling any gastric contents. This non-productive vomiting occurs when the brain’s reflex is triggered, causing powerful contractions that simulate the act of throwing up. The sensation is intensely uncomfortable and is generally accompanied by nausea. Understanding the underlying mechanisms and triggers is the first step toward finding relief.
The Mechanics of Retching
Retching is a reflex coordinated by the vomiting center located in the medulla oblongata of the brainstem. This process involves spasmodic contractions of the abdominal wall muscles and the diaphragm. The retching phase is characterized by alternating opposition between inspiratory movements of the chest and expiratory contractions of the abdominal muscles, all while the glottis is closed.
The reason this effort remains “dry” is often due to the lower esophageal sphincter (LES) remaining tightly closed. While the stomach contents are forcefully displaced upward toward the esophagus, the LES does not fully relax to permit expulsion, or the stomach is completely empty. The body performs the physical work of vomiting, but the final expulsive step is blocked or unnecessary.
Causes Originating in the Digestive System
Many instances of dry heaving are rooted in irritation or dysfunction within the gastrointestinal (GI) tract. Gastroesophageal Reflux Disease (GERD) is a frequent culprit, where stomach acid backs up into the esophagus, causing irritation. This acid reflux triggers the gag reflex, initiating the retching sequence without causing the full expulsion of stomach contents.
Inflammatory conditions affecting the stomach lining also send distress signals that can trigger retching. Gastritis and peptic ulcers create chronic irritation that can activate the vomiting center. Even when the stomach is empty, the body may continue to retch as it attempts to clear the perceived irritant.
A distinct digestive cause is retching on an empty stomach after a period of intense vomiting. Delayed gastric emptying, known as gastroparesis, can also cause dry heaving because food remains in the stomach longer than it should, leading to chronic irritation and a sensation of fullness.
Systemic and Non-Gastrointestinal Triggers
Dry heaves are not exclusively a digestive issue, as the vomiting center can be activated by signals from outside the GI tract. Neurological triggers, such as severe migraine headaches, are associated with intense nausea and retching. The same brain pathways that transmit headache pain can also stimulate the vomiting center.
Disturbances in the inner ear, which controls balance, can cause motion sickness that manifests as dry heaves. This occurs when the brain receives conflicting sensory information, activating the retching reflex. Certain medications, including some antidepressants, antibiotics, and chemotherapy drugs, list nausea and dry heaving as known side effects, directly affecting the brain’s chemoreceptor trigger zone.
Psychological factors are powerful triggers, as the mind-gut connection is well-established. Acute anxiety, intense stress, or panic attacks can cause a physical manifestation of distress, including muscle tension that contributes to dry heaving. Respiratory irritation, such as a prolonged coughing fit or post-nasal drip, can physically stimulate the back of the throat, initiating the non-productive vomiting reflex.
Metabolic imbalances, such as low blood sugar (hypoglycemia) or the systemic effects of excessive alcohol consumption, can also activate the vomiting center. These systemic issues signal a toxicity or imbalance that the brain attempts to correct. Pregnancy, specifically “morning sickness,” is a hormonal cause that frequently involves dry heaving due to elevated levels of hormones like human chorionic gonadotropin (hCG).
Warning Signs and When to Seek Medical Care
While dry heaves are often temporary and resolve on their own, persistent symptoms warrant professional medical evaluation. If retching continues for more than 24 to 48 hours without relief, contact a healthcare provider. Ongoing dry heaving can lead to severe dehydration, which requires medical attention to correct fluid and electrolyte imbalances.
Immediate medical attention is necessary if dry heaves are accompanied by more severe symptoms that suggest a serious underlying condition. These include signs of significant dehydration (extreme thirst or little to no urination), severe abdominal or chest pain, a high fever, a rapid pulse, or any confusion or disorientation.