Retching (also known as dry heaving) is the reverse movement (

retroperistalsis Retroperistalsis is the reverse of the involuntary smooth muscle contractions of peristalsis. It usually occurs as a precursor to vomiting. Local irritation of the stomach, such as bacteria or food poisoning, activates the emetic center of the ...

) of the

stomach The stomach is a muscular, hollow organ in the upper gastrointestinal tract of Human, humans and many other animals, including several invertebrates. The Ancient Greek name for the stomach is ''gaster'' which is used as ''gastric'' in medical t ...

and

esophagus The esophagus (American English), oesophagus (British English), or œsophagus (Œ, archaic spelling) (American and British English spelling differences#ae and oe, see spelling difference) all ; : ((o)e)(œ)sophagi or ((o)e)(œ)sophaguses), c ...

without

vomiting Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteritis, pre ...

. It can be caused by bad smells or choking, or by withdrawal from certain medications, or after vomiting has completed. Retching can also occur as a result of an emotional response or from stress, which produces the same physical reaction. The function is thought to be mixing gastric contents with intestinal refluxate in order to buffer the former and give it momentum in preparation of vomiting. Treatments include medication and correction of the

fluid In physics, a fluid is a liquid, gas, or other material that may continuously motion, move and Deformation (physics), deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are M ...

and electrolyte balance.

Physiology

The retching phase is characterized by a series of violent spasmodic abdomino-

thoracic The thorax (: thoraces or thoraxes) or chest is a part of the anatomy of mammals and other tetrapod animals located between the neck and the abdomen. In insects, crustaceans, and the extinct trilobites, the thorax is one of the three main ...

contractions with the

glottis The glottis (: glottises or glottides) is the opening between the vocal folds (the rima glottidis). The glottis is crucial in producing sound from the vocal folds. Etymology From Ancient Greek ''γλωττίς'' (glōttís), derived from ''γ ...

closed. During this time, the inspiratory (inhalatory) movements of the chest wall and diaphragm are opposed by the expiratory contractions of the abdominal musculature. At the same time, movements of the

and its contents take place. Whereas a patient will complain of disagreeable sensations during

nausea Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 d ...

, speech is not possible during retching. The characteristic movements furnish a ready diagnostic sign of the retching phase. Schindler (1937) studied retching on two occasions during

gastroscopy Esophagogastroduodenoscopy (EGD) or oesophagogastroduodenoscopy (OGD), also called by various other names, is a diagnostic endoscopic procedure that visualizes the upper part of the gastrointestinal tract down to the duodenum. It is considered ...

and noted that longitudinal folds appeared in the previously smooth antrum, thickened quickly, came together and completely closed the antrum. Retching involves a deep inspiration against a closed

. This, along with contraction of the abdomen, leads to a pressure difference between the abdominal and thoracic cavities. As a result, the stomach and gastric contents are displaced upwards toward the thoracic cavity. Retching comprises a rhythmically alternating (about once per second) elevation and descension of the entire apparatus in synchrony with the movement of the diaphragm. The function of retching may be to mix gastric contents with intestinal refluxate to buffer gastric contents before gastroesophageal reflux and to impart a momentum to the gastric contents before vomiting. Airway protection during retching is accomplished by glottal closure during retches and constriction of the upper esophageal sphincter between retches.

Versus vomiting

Vomiting (the expulsion of gastric contents) is usually preceded by retching, but retching and vomiting can occur separately and involve different sets of muscles. During a retch, thoracic pressure is ''decreased'' and abdominal pressure is ''increased'', which may serve to position gastric contents and overcome esophageal resistance. Conversely, a vomit occurs with ''increased'' thoracic and abdominal pressure. Retches and vomits are commonly lumped together in behavioral analyses and consequently the neural controls for these processes are not well delineated.

Treatments

The treatments for significant retching include correction of fluid and electrolyte balance, nutritional support and medications like

phenothiazines Phenothiazine, abbreviated PTZ, is an organic compound that has the formula S(C6H4)2NH and is related to the thiazine-class of heterocyclic compounds. Derivatives of phenothiazine are highly bioactive and have widespread use and rich history. ...

(such as Compazine and Phenergan),

5-HT3 antagonist The 5-HT3 antagonists, informally known as "setrons", are a class of drugs that act as receptor antagonists at the 5-HT3 receptor, a subtype of serotonin receptor found in terminals of the vagus nerve and in certain areas of the brain. With th ...

(such as Zofran), dopamine receptor antagonists (such as Reglan),

antihistamines Antihistamines are drugs which treat allergic rhinitis, common cold, influenza, and other allergies. Typically, people take antihistamines as an inexpensive, generic (not patented) drug that can be bought without a prescription and provides r ...

( Antivert, Dramamine,

Benadryl Benadryl is a brand of various antihistamine medications used to stop allergy, allergies, whose content varies in different countries, but which includes some combination of diphenhydramine, acrivastine, or cetirizine. It is sold by Kenvue and ...

) and anticholinergics ( scopolamine). Alternative approaches are also available. The best-studied alternative therapy is perhaps the use of

acupressure Acupressure is an alternative medicine technique often used in conjunction with acupuncture or reflexology. It is based on the concept of "life energy" (qi), which purportedly flows through "meridians" in the body. There is no scientific evidenc ...

for pregnancy-related nausea and vomiting. Wristbands with acupressure buttons are commercially available. An implanted device with attached electrodes into the gastric wall can be an option for patients with refractory nausea and vomiting.

References

{{reflist Reflexes Digestive disease symptoms Vomiting

Physiology

Versus vomiting

Treatments

See also

References