Hiccup

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Hiccup
Other namesSingultus, hiccough, synchronous diaphragmatic flutter (SDF)
Pronunciation
Specialty Otorhinolaryngology   OOjs UI icon edit-ltr-progressive.svg

A hiccup (scientific name singultus, from Latin for "sob, hiccup"; also spelled hiccough) is an involuntary contraction (myoclonic jerk) of the diaphragm that may repeat several times per minute. The hiccup is an involuntary action involving a reflex arc.[ citation needed ] Once triggered, the reflex causes a strong contraction of the diaphragm followed about a quarter of a second later by closure of the vocal cords, which results in the "hic" sound.

Contents

Hiccups may occur individually, or they may occur in bouts. The rhythm of the hiccup, or the time between hiccups, tends to be relatively constant. A bout of hiccups generally resolves itself without intervention, although many home remedies are often used to attempt to shorten the duration. [1] Medical treatment is occasionally necessary in cases of chronic hiccups. [2]

Incidence

Hiccups affect people of all ages, even being observed in utero. They become less frequent with advancing age. Intractable hiccups, lasting more than a month, are more common in adults. While males and females are affected equally often, men are more likely to develop protracted and intractable hiccups. [3]

Along with humans, hiccups have been studied and observed in cats, rats, rabbits, dogs, and horses. [4]

Signs and symptoms

Gnome-mime-sound-openclipart.svg
Hiccup sound
The sound of a human hiccup
Problems playing this file? See media help.
Histogram of period (in seconds) between each hiccup in a sequence of 50 samples in about 10 minutes. Mean: 11.40 s. Median: 10.715 s. Standard deviation: 2.88 s. Data set ranges from 6.28 s to 21.36 s. Hiccup histogram.svg
Histogram of period (in seconds) between each hiccup in a sequence of 50 samples in about 10 minutes. Mean: 11.40 s. Median: 10.715 s. Standard deviation: 2.88 s. Data set ranges from 6.28 s to 21.36 s.

A hiccup consists of a single or a series of breathing diaphragm spasms, of variable spacing and duration, and a brief (less than one half second), unexpected, shoulder, abdomen, throat, or full body tremor.

Causes

Pathophysiological causes

Hiccups may be triggered by a number of common human conditions. In rare cases, they can be a sign of serious medical problems such as myocardial infarction. [12]

Pre-phrenic nucleus irritation of medulla

CNS disorders

Nerve damage

Other known associations

  • Although no clear pathophysiological mechanism has been described, hiccups is known to have been the initial symptom of Plasmodium vivax malaria in at least one documented case. [15]

Evolutionary theories

The burping reflex hypothesis

A leading hypothesis is that hiccups evolved to facilitate greater milk consumption in young mammals. [8] The coordination of breathing and swallowing during suckling is a complicated process. Some air inevitably enters the stomach, occupying space that could otherwise be optimally used for calorie-rich milk.

The hypothesis suggests that the presence of an air bubble in the stomach stimulates the sensory (afferent) limb of the reflex through receptors in the stomach, esophagus and along the underside of the diaphragm. This triggers the active part of the hiccup (efferent limb), sharply contracting the muscles of breathing and relaxing the muscles of the esophagus, then closing the vocal cords to prevent air from entering the lungs. This creates suction in the chest, pulling air from the stomach up into the esophagus. As the respiratory muscles relax the air is expelled through the mouth, effectively "burping" the animal.[ citation needed ]

There are a number of characteristics of hiccups that support this theory. The burping of a suckling infant may increase its capacity for milk by more than 15-25%, bringing a significant survival advantage. There is a strong tendency for infants to get hiccups, and although the reflex persists throughout life it decreases in frequency with age. The location of the sensory nerves that trigger the reflex suggests it is a response to a condition in the stomach. The component of the reflex that suppresses peristalsis in the esophagus while the airway is being actively blocked suggests the esophagus is involved. Additionally, hiccups are only described in mammals -– the group of animals that share the trait of suckling their young.[ citation needed ]

Phylogenetic hypothesis

An international respiratory research group composed of members from Canada, France, and Japan proposed that the hiccup is an evolutionary remnant of earlier amphibian respiration. [16] Amphibians such as tadpoles gulp air and water across their gills via a rather simple motor reflex akin to mammalian hiccuping. The motor pathways that enable hiccuping form early during fetal development, before the motor pathways that enable normal lung ventilation form. Thus, the hiccup is evolutionarily antecedent to modern lung respiration.

Additionally, this group (C. Straus et al.) points out that hiccups and amphibian gulping are inhibited by elevated CO2 and may be stopped by GABAB receptor agonists, illustrating a possible shared physiology and evolutionary heritage. These proposals may explain why premature infants spend 2.5% of their time hiccuping, possibly gulping like amphibians, as their lungs are not yet fully formed. [17]

The phylogenetic hypothesis may explain hiccups as an evolutionary remnant, held over from our amphibious ancestors. [18]

Duration

Episodes of hiccups usually last under 30 minutes. Prolonged attacks, while rare, can be serious. Root causes of prolonged hiccups episodes are difficult to diagnose.[ failed verification ] Such attacks can cause significant morbidity and even death. [3] An episode lasting more than a few minutes is termed a bout; a bout of over 48 hours is termed persistent or protracted. Hiccups lasting longer than a month are termed intractable. In many cases, only a single hemidiaphragm, usually the left one, is affected, although both may be involved. [3]

Treatment

Hiccups are normally waited out, as any fit of them will usually pass quickly. Folk 'cures' for hiccups are common and varied. Hiccups are treated medically only in severe and persistent (termed "intractable") cases. [3]

Numerous medical remedies exist but no particular treatment is known to be especially effective, generally because of a lack of high-quality evidence. [19] [20]

A vagus nerve stimulator has been used with an intractable case of hiccups. "It sends rhythmic bursts of electricity to the brain by way of the vagus nerve, which passes through the neck. The Food and Drug Administration approved the vagus nerve stimulator in 1997 as a way to control seizures in some patients with epilepsy." [21]

In one person, persistent digital rectal massage coincided with terminating intractable hiccups. [22]

Folk remedies

There are many superstitious and folk remedies for hiccups, including headstanding, drinking a glass of water upside-down, being frightened by someone, breathing into a bag, eating a large spoonful of peanut butter and placing sugar on or under the tongue. [23] [24]

Acupressure, either through actual function or placebo effect, may cure hiccups in some people. For example, one technique is to relax the chest and shoulders and find the deepest points of the indentations directly below the protrusions of the collarbones. The index or middle fingers are inserted into the indents and pressed firmly for sixty seconds as long, deep breaths are taken. [25]

A simple treatment involves increasing the partial pressure of CO2 and inhibiting diaphragm activity by holding one's breath or rebreathing into a paper bag. [26] Other potential remedies suggested by NHS Choices include pulling the knees up to the chest and leaning forward, sipping ice-cold water and swallowing some granulated sugar. [27]

A breathing exercise called Supra-supramaximal inspiration (SSMI) has been shown to stop persistent hiccups. [28] It combines the three principles of hypercapnia, diaphragm immobilization, and positive airway pressure. First, the subject must exhale completely, then take a deep breath. Then, they must hold their breath for ten seconds. After ten seconds, they must take another small breath without exhaling, then hold their breath for five seconds. Again, without exhaling, they must take another small breath and hold their breath for five seconds. Upon exhaling, the hiccups should be gone.

Drinking through a straw with the ears plugged is a folk remedy that can be successful. [29] In 2021 a scientific tool with a similar basis was tested on 249 hiccups subjects; the results were published in the Journal of the American Medical Association (JAMA). [30] [29] This device is named FISST (Forced Inspiratory Suction and Swallow Tool) and branded as "HiccAway". This study supports the use of FISST as an option to stop transient hiccups, with more than 90% of participants reporting better results than home remedies. HiccAway stops hiccups by forceful suction that is being generated by diaphragm contraction (phrenic nerve activity), followed by swallowing the water, which requires epiglottis closure. [31]

Society and culture

The word hiccup itself was created through imitation. The alternative spelling of hiccough results from the association with the word cough. [32]

In Baltic, German, Hungarian, Indian, Romanian, Slavic, Turkish, Greek and Albanian tradition, as well as among some tribes in Kenya, for example in the folklore of the Luo people, it is said that hiccups occur when the person experiencing them is being talked about by someone not present. [38] [39]

See also

Related Research Articles

<span class="mw-page-title-main">Vagus nerve</span> Main nerve of the parasympathetic nervous system

The vagus nerve, also known as the tenth cranial nerve, cranial nerve X, or simply CN X, is a cranial nerve that carries sensory fibers that create a pathway that interfaces with the parasympathetic control of the heart, lungs, and digestive tract. It comprises two nerves—the left and right vagus nerves, each containing about 100,000 fibres—but they are typically referred to collectively as a single subsystem.

<span class="mw-page-title-main">Esophagus</span> Vertebrate organ through which food passes to the stomach

The esophagus or oesophagus, colloquially known also as the food pipe, food tube, or gullet, is an organ in vertebrates through which food passes, aided by peristaltic contractions, from the pharynx to the stomach. The esophagus is a fibromuscular tube, about 25 cm (10 in) long in adults, that travels behind the trachea and heart, passes through the diaphragm, and empties into the uppermost region of the stomach. During swallowing, the epiglottis tilts backwards to prevent food from going down the larynx and lungs. The word oesophagus is from Ancient Greek οἰσοφάγος (oisophágos), from οἴσω (oísō), future form of φέρω + ἔφαγον.

Swallowing, also called deglutition or inglutition in scientific contexts, is the process in the body of a human or other animal that allows for a substance to pass from the mouth, to the pharynx, and into the esophagus, while shutting the epiglottis. Swallowing is an important part of eating and drinking. If the process fails and the material goes through the trachea, then choking or pulmonary aspiration can occur. In the human body the automatic temporary closing of the epiglottis is controlled by the swallowing reflex.

<span class="mw-page-title-main">Hiatal hernia</span> Type of hernia

A hiatal hernia or hiatus hernia is a type of hernia in which abdominal organs slip through the diaphragm into the middle compartment of the chest. This may result in gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR) with symptoms such as a taste of acid in the back of the mouth or heartburn. Other symptoms may include trouble swallowing and chest pains. Complications may include iron deficiency anemia, volvulus, or bowel obstruction.

<span class="mw-page-title-main">Phrenic nerve</span> Nerve controlling the diaphragm

The phrenic nerve is a mixed motor/sensory nerve that originates from the C3-C5 spinal nerves in the neck. The nerve is important for breathing because it provides exclusive motor control of the diaphragm, the primary muscle of respiration. In humans, the right and left phrenic nerves are primarily supplied by the C4 spinal nerve, but there is also a contribution from the C3 and C5 spinal nerves. From its origin in the neck, the nerve travels downward into the chest to pass between the heart and lungs towards the diaphragm.

<span class="mw-page-title-main">Thoracic diaphragm</span> Sheet of internal skeletal muscle

The thoracic diaphragm, or simply the diaphragm, is a sheet of internal skeletal muscle in humans and other mammals that extends across the bottom of the thoracic cavity. The diaphragm is the most important muscle of respiration, and separates the thoracic cavity, containing the heart and lungs, from the abdominal cavity: as the diaphragm contracts, the volume of the thoracic cavity increases, creating a negative pressure there, which draws air into the lungs. Its high oxygen consumption is noted by the many mitochondria and capillaries present; more than in any other skeletal muscle.

The control of ventilation is the physiological mechanisms involved in the control of breathing, which is the movement of air into and out of the lungs. Ventilation facilitates respiration. Respiration refers to the utilization of oxygen and balancing of carbon dioxide by the body as a whole, or by individual cells in cellular respiration.

The pharyngeal reflex or gag reflex is a reflex muscular contraction of the back of the throat, evoked by touching the roof of the mouth, back of the tongue, area around the tonsils, uvula, and back of the throat. It, along with other aerodigestive reflexes such as reflexive pharyngeal swallowing, prevents objects in the oral cavity from entering the throat except as part of normal swallowing and helps prevent choking, and is a form of coughing. The pharyngeal reflex is different from the laryngeal spasm, which is a reflex muscular contraction of the vocal cords.

<span class="mw-page-title-main">Nissen fundoplication</span> Surgical procedure to treat gastric reflux and hiatal hernia

A Nissen fundoplication, or laparoscopic Nissen fundoplication when performed via laparoscopic surgery, is a surgical procedure to treat gastroesophageal reflux disease (GERD) and hiatal hernia. In GERD, it is usually performed when medical therapy has failed; but, with a Type II (paraesophageal) hiatus hernia, it is the first-line procedure. The Nissen fundoplication is total (360°), but partial fundoplications known as Thal, Belsey, Dor, Lind, and Toupet fundoplications are alternative procedures with somewhat different indications and outcomes.

Aerophagia is a condition of excessive air swallowing, which goes to the stomach instead of the lungs. Aerophagia may also refer to an unusual condition where the primary symptom is excessive flatus (farting), belching (burping) is not present, and the actual mechanism by which air enters the gut is obscure or unknown. Aerophagia in psychiatry is sometimes attributed to nervousness or anxiety.

<span class="mw-page-title-main">Inferior pharyngeal constrictor muscle</span> Skeletal muscle of the pharynx

The inferior pharyngeal constrictor muscle is a skeletal muscle of the neck. It is the thickest of the three outer pharyngeal muscles. It arises from the sides of the cricoid cartilage and the thyroid cartilage. It is supplied by the vagus nerve. It is active during swallowing, and partially during breathing and speech. It may be affected by Zenker's diverticulum.

<span class="mw-page-title-main">Rumination syndrome</span> Medical condition

Rumination syndrome, or merycism, is a chronic motility disorder characterized by effortless regurgitation of most meals following consumption, due to the involuntary contraction of the muscles around the abdomen. There is no retching, nausea, heartburn, odour, or abdominal pain associated with the regurgitation as there is with typical vomiting, and the regurgitated food is undigested. The disorder has been historically documented as affecting only infants, young children, and people with cognitive disabilities . It is increasingly being diagnosed in a greater number of otherwise healthy adolescents and adults, though there is a lack of awareness of the condition by doctors, patients, and the general public.

The cough reflex occurs when stimulation of cough receptors in the respiratory tract by dust or other foreign particles produces a cough, which causes rapidly moving air which usually remove the foreign material before it reaches the lungs. This typically clears particles from the bronchi and trachea, the tubes that feed air to lung tissue from the nose and mouth. The larynx and carina are especially sensitive. Cough receptors in the surface cells (epithelium) of the respiratory tract are also sensitive to chemicals. Terminal bronchioles and even the alveoli are sensitive to chemicals such as sulfur dioxide gas or chlorine gas.

<span class="mw-page-title-main">Vagovagal reflex</span> Reflex circuits in the gastrointestinal tract

Vagovagal reflex refers to gastrointestinal tract reflex circuits where afferent and efferent fibers of the vagus nerve coordinate responses to gut stimuli via the dorsal vagal complex in the brain. The vagovagal reflex controls contraction of the gastrointestinal muscle layers in response to distension of the tract by food. This reflex also allows for the accommodation of large amounts of food in the gastrointestinal tracts.

<span class="mw-page-title-main">Vomiting</span> Involuntary, forceful expulsion of stomach contents, typically via the mouth

Vomiting is the involuntary, forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose.

A vagal maneuver is an action used to stimulate the parasympathetic nervous system by activating the vagus nerve. The vagus nerve is the longest nerve of the autonomic nervous system and helps regulate many critical aspects of human physiology, including heart rate, blood pressure, sweating, and digestion through the release of acetylcholine. Common maneuvers that activate the vagus nerve include the Valsalva maneuver and carotid sinus massage, which can serve diagnostic or therapeutic functions.

<span class="mw-page-title-main">Pharynx</span> Part of the throat that is behind the mouth and nasal cavity

The pharynx is the part of the throat behind the mouth and nasal cavity, and above the esophagus and trachea. It is found in vertebrates and invertebrates, though its structure varies across species. The pharynx carries food to the esophagus and air to the larynx. The flap of cartilage called the epiglottis stops food from entering the larynx.

Cricopharyngeal spasms occur in the cricopharyngeus muscle of the pharynx. Cricopharyngeal spasm is an uncomfortable but harmless and temporary disorder.

Obligate nasal breathing describes a physiological instinct to breathe through the nose as opposed to breathing through the mouth.

<span class="mw-page-title-main">Human digestive system</span> Digestive system in humans

The human digestive system consists of the gastrointestinal tract plus the accessory organs of digestion. Digestion involves the breakdown of food into smaller and smaller components, until they can be absorbed and assimilated into the body. The process of digestion has three stages: the cephalic phase, the gastric phase, and the intestinal phase.

References

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  8. 1 2 Howes, D. (2012). "Hiccups: A new explanation for the mysterious reflex". BioEssays. 34 (6): 451–453. doi:10.1002/bies.201100194. PMC   3504071 . PMID   22377831.
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  21. ↑ Schaffer, Amanda (10 January 2006). "A Horrific Case of Hiccups, a Novel Treatment". The New York Times . Retrieved 24 April 2008.
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  23. ↑ Engleman EG, Lankton J, Lankton B (December 1971). "Granulated sugar as treatment for hiccups in conscious patients". The New England Journal of Medicine. 285 (26): 1489. doi:10.1056/nejm197112232852622. PMID   5122907.
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  29. 1 2 Ellis, Ralph (22 June 2021). "Inventor Says His New Straw Will Cure Hiccups". Medscape.
  30. ↑ Alvarez, James; Anderson, Jane Margaret; Snyder, Patrick Larry; Mirahmadizadeh, Alireza; Godoy, Daniel Agustin; Fox, Mark; Seifi, Ali (2021). "Evaluation of the Forced Inspiratory Suction and Swallow Tool to Stop Hiccups". JAMA Network Open. 4 (6): e2113933. doi:10.1001/jamanetworkopen.2021.13933. ISSN   2574-3805. PMC   8214157 . PMID   34143196.
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