Hiccups, also known as singultus, are involuntary contractions of the diaphragm that occur in quick succession. They are caused by an involuntary reflex arc that involves the vagus nerve and phrenic nerve. Hiccups may occur individually or in bouts, and tend to resolve on their own, though many home remedies are used to try to shorten their duration. Medical treatment is sometimes necessary for cases of chronic hiccups.

1. A hiccup or hiccough ( /ˈhɪkəp/ HIK-əp) is a contraction of the
diaphragm that may repeat several times per minute. In medicine it is
known as synchronous diaphragmatic flutter (SDF), or singultus, from
the Latin singult, "the act of catching one's breath while sobbing".[1]
The
hiccup is an involuntary action involving a reflex arc.[1] Once triggered,
the reflex causes a strong contraction of the diaphragm followed about
0.25 seconds later by closure of the vocal cords, which results in the
classic hic sound. At the same time, the normal peristalsis of the
esophagus is suppressed.
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, in general, resolves itself without intervention,
although many home remedies are often used to attempt to shorten
the duration.[2]
Medical treatment is occasionally necessary in cases of
chronic hiccups.
Contents
 1 Why Hiccups Evolved
o 1.1 Phylogenetic hypothesis
o 1.2 Clearance of air from stomach
 2 Signs and symptoms

2.  3 Causes
 4 Pathologic Causes for Hiccups
o 4.1 Pre-phrenic nucleus irritation of medulla
o 4.2 Infections
o 4.3 CNS disorders
o 4.4 Nerve damage/irritation
 5 Treatment
 6 Society and culture
 7 See also
 8 References
 9 Further reading
 10 External links
Why Hiccups Evolved
This section may require cleanup to meet Wikipedia's quality
standards. No cleanup reason has been specified. Please help
improve this section if you can. (April 2011)
Hiccup sound

3. Menu
0:00
The sound of a human hiccup
Problems listening to this file? See media help.
Phylogenetic hypothesis
Researchers at the Respiratory Research Group at the University of
Calgary in Alberta, Canada, propose that the hiccup is an evolutionary
remnant of earlier amphibian respiration. Amphibians such as tadpoles
gulp air and water across their gills via a rather simple motor reflex akin
to mammalian hiccuping.[3]
In support of this idea, they observe that
the motor pathways that enable hiccuping from early during fetal
development, before the motor pathways that enable normal lung
ventilation form. Thus, according to recapitulation theory the hiccup is
evolutionarily antecedent to modern lung respiration. Additionally,
they point 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. Fetal intrauterine hiccups are of two types. The

4. physiological type occurs prior to twenty-eight weeks after conception
and tend to last five to ten minutes. These hiccups are part of fetal
development and are associated with the myelination of the phrenic
nerve, which primarily controls the thoracic diaphragm. The phylogeny
hypothesis explains how the hiccup reflex might have evolved, and if
there is not an alternate explanation it may explain hiccups as an
evolutionary remnant, held-over from our amphibious ancestors.
This hypothesis has been questioned because of the existence of the
afferent loop of the reflex, the fact that it does not explain the reason
for glottic closure, and because the very short contraction of the hiccup
is unlikely to have a significant strengthening effect on the slow-twitch
muscles of respiration.
Clearance of air from stomach
A more recent explanation by Howes in 2012 suggests that hiccups may
have evolved along with other reflexes developed in mammals that
allow them to coordinate suckling milk and breathing[4]
. Hiccups are
only found in mammals, and are most common in infants, becoming
rarer as mammals age. This may suggest that they evolved to allow air
trapped in the stomach of suckling infants to escape, allowing more
milk to be ingested. The hypothesis suggests that the air bubble in the
stomach stimulates the sensory limb of the reflex at receptors in the
stomach, esophagus and along the diaphragm. This triggers the hiccup,
which creates suction in the chest, pulling air from the stomach up and
out through the mouth, effectively burping the animal. This theory is
supported by the strong tendency for infants to get hiccups, the
component of the reflex that suppresses peristalsis in the esophagus,
and the existence of hiccups only in milk-drinking mammals.

5. Signs and symptoms
 A single or a series of breathing diaphragm spasms, of variable
spacing and duration.
 A brief (less than one half second), unexpected, shoulder,
abdomen, throat, or full body tremor.
 Hiccups might be easily heard as a chirp, squeak, "hupp", or if
controlled, a quick inhaling gasp, sigh, or sniff.
 The victim might complain of brief but distracting or painful,
frequent or occasional interruptions in normal breath, with
sudden momentary pain of the throat, chest, or abdomen.
Causes
This section needs additional citations for verification. (February
2012)
 Overeating[citation needed]
 Rapid eating [4]
 Sudden temperature changes[citation needed]
 Carbonated beverages, alcohol, dry breads, and some spicy
foods.[5]
 Laughing[6]
 Certain drugs (opiates and benzodiazepines)[citation needed]
 Tobacco use (nicotine)[citation needed]
Pathologic Causes for Hiccups

6. Hiccups may be triggered by a number of common human conditions.
Rarely, they can be a sign of serious medical problems.
Pre-phrenic nucleus irritation of medulla
Clinical case reports mention that lesions of the medulla that involve
the area slightly ventral and lateral to nucleus and tractus solitarius
cause hiccups. One (of several) explanations for this finding is that such
a lesion “irritates” descending information from nucleus solitarius to
the phrenic nucleus. The phrenic nucleus consists of a functionally
related group of cell bodies in the ventral horn from C3-C5. Axons
arising from the phrenic nucleus comprise the phrenic nerve, which
innervates the diaphragm. The hiccups result from spasmodic lowering
of the diaphragm that causes a short, sharp inspiratory cough. Brain
stem lesions involving the area ventral and lateral to nucleus and
tractus solitarius result in hiccup.[7]
 Metabolic diseases[citation needed]
 Diabetes[citation needed]
 Kidney failure[citation needed]
 Electrolyte imbalance[citation needed]
 Deviated septum[citation needed]
Infections
 Pneumonia[citation needed]
 CLD[citation needed]

7. CNS disorders
 Stroke[citation needed]
 Multiple sclerosis[8]
 Tumors[citation needed]
 Meningitis[citation needed]
 Encephalitis[citation needed]
 Traumatic brain injury[citation needed]
Nerve damage/irritation
 Vagus and phrenic nerve involvement[citation needed]
 Laryngitis[citation needed]
 Cysts]
 Goiter
 Gastroesophageal reflux
Treatment
Numerous medical remedies exist but no particular treatment is known
to be especially effective.[9]
Many drugs have been used, such as
baclofen, chlorpromazine, metoclopramide, gabapentin, and various
proton-pump inhibitors. Hiccups that are secondary to some other
cause like gastroesophageal reflux disease or esophageal webs are
dealt with by treating the underlying disorder. Home treatment like
drinking water is effective. A simple treatment involves increasing the
partial pressure of CO2 and inhibiting diaphragm activity by holding

8. one’s breath or rebreathing into a paper bag. Vagus nerve stimulation
can improve hiccups, done at home by irritating the pharynx through
swallowing dry bread or crushed ice, or by applying traction to the
tongue, or by stimulating the gag reflex. The phrenic nerve can be
blocked temporarily with injection of 0.5% procaine, or permanently
with bilateral phrenicotomy or other forms of surgical destruction. Even
this rather drastic treatment does not cure some cases, however.
In Plato's Symposium, Aristophanes has a case of the hiccups and is
advised by Eryximachus, a physician, to cure them by holding his
breath, or, failing that, by gargling or provoking sneezing. This ancient
recommendation can be compared with the vagal nerve stimulation
techniques mentioned previously.
An anecdotal medical approach is to install lidocaine liniment 3% or gel
2% in the external ear. Somehow this creates a vagus nerve-triggering
reflex through its extensions to the external ear and tympanus (ear
drum). The effect can be immediate, and also have lasting effect after
the lidocaine effect expires after about two hours.[10]
A solution involving sugar placed on or under the tongue was cited in
the December 23, 1971 issue of the New England Journal of
Medicine.[11]
Hiccups are treated medically only in severe and persistent (termed
"intractable") cases, such as in the case of Jennifer Mee, a 19-year-old
woman who, in 2007, hiccuped continuously for five weeks.[12]
Haloperidol (Haldol, an anti-psychotic and sedative), metoclopramide
(Reglan, a gastrointestinal stimulant), and chlorpromazine (Thorazine,
an anti-psychotic with strong sedative effects) are used in cases of
intractable hiccups. Effective treatment with sedatives often requires a

9. dose that renders the person either unconscious or highly lethargic.
Hence, medicating with sedatives is only appropriate short-term, as the
affected individual cannot continue with normal life activities while
under their effect.
Persistent and intractable hiccups due to electrolyte imbalance
(hypokalemia, hyponatremia) may benefit from drinking a carbonated
beverage containing salt to normalize the potassium-sodium balance in
the nervous system.[citation needed]
The carbonation promotes quicker
absorption. Carbonated beverages, including beer, by themselves may
provoke hiccups in some people.[citation needed]
The administration of intranasal vinegar was found to ease the chronic
and severe hiccups of a three-year old Japanese girl. Vinegar may
stimulate the dorsal wall of the nasopharynx, where the pharyngeal
branch of the glossopharyngeal nerve (the afferent of the hiccup reflex
arc) is located.[13]
Dr. Bryan R. Payne, a neurosurgeon at the Louisiana State University
Health Sciences Center in New Orleans, has had some success with an
experimental procedure in which a vagus nerve stimulator is implanted
in the upper chest of patients 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."[14]
Society and culture
American Charles Osborne had hiccups for 68 years, from 1922 to
February 1990 [2], and was entered in the Guinness World Records as

10. the man with the longest attack of hiccups an estimated 430 million
hiccups later. [15]
In 2007, Florida teenager Jennifer Mee gained media
fame for hiccuping around 50 times per minute for more than five
weeks; she was given the nickname "Hiccup Girl".[16][17] Briton
Christopher Sands had hiccupped an estimated 10 million times in a 15-
month period from February 2007 to May 2009 which were eventually
discovered to be due to a tumor on his brain stem had been pushing on
nerves, causing him to hiccup every two seconds, 12 hours a day, an
affliction that meant that he could hardly eat or sleep and finally
stopped in 2009 following brain surgery.[18]
In Slavic and Baltic folklore, it is said that hiccups occur when the
person experiencing them is being talked about by someone not
present. Hiccups in Indian and Arabic folklore are similarly said to occur
when the person experiencing them is being thought of by somebody
close.[citation needed]
See also
 Getting the wind knocked out of you
 Sneeze
 Cough
 Mr. Hiccup
References
1. ^ a b
Wilkes, Garry (2 August 2007). "Hiccups". eMedicine.
Medscape. Retrieved 2009-04-22.
2. ^ "Hiccups". Home Remedies. Retrieved 5 November 2011.

11. 3. ^ Straus, C.; Vasilakos, K; Wilson, RJ; Oshima, T; Zelter, M;
Derenne, JP; Similowski, T; Whitelaw, WA (February 2003).
"A phylogenetic hypothesis for the origin of hiccough".
BioEssays 25 (2): 182–188. doi:10.1002/bies.10224.
PMID 12539245.
4. ^ a b
Howes, D. (2012). "Hiccups: A new explanation for the
mysterious reflex". BioEssays: n/a.
doi:10.1002/bies.201100194. edit
5. ^ "Hiccups Happen!". University of Maryland Hospital for
Children. Retrieved 2012-04-02.
6. ^ Meadow Milano. "Causes of Hiccups". Retrieved 2012-04-
02.
7. ^ [1], additional text.
8. ^ Rawiphan Witoonpanich; Busaya Pirommai, Supoch
Tunlayadechanont (Oct 2004). "Hiccups and multiple
sclerosis" (PDF). Journal of the Medical Association of
Thailand. PubMed. Retrieved 2012-06-23.
9. ^ Porter, Robert S., ed. (2011). "Hiccups". The Merck Manual
Online. Merck Sharp & Dohme.
10. ^ "Miracle hiccough cure gets the attention it
deserves". BMJ. 2006-10-07.
11. ^ Engleman EG, Lankton J, Lankton B (December 1971).
"Granulated sugar as treatment for hiccups in conscious
patients". N. Engl. J. Med. 285 (26): 1489.
doi:10.1056/NEJM197112232852622.PMID 5122907.

12. Boswell, Wendy (2007-03-25). "MacGyver Tip: Cure hiccups
with sugar". The People's Pharmacy (Lifehacker). Retrieved
2009-11-30.
12. ^ "Teen's hiccups stop after five weeks". ABC News
Online. 2007-03-02 (Broken Link).
13. ^ Iwasaki, N; et al. (May 2007). "Hiccup treated by
administration of intranasal vinegar". No to Hattatsu 39 (3):
202–5. PMID 17515134.
14. ^ Schaffer, Amanda (2006-01-10). "A Horrific Case of
Hiccups, a Novel Treatment". New York Times. Retrieved
2008-04-24.
15. ^ "Survivor of 68-Year Hiccup Spell Dies" (Sunrise
Edition: 2.B. ed.). Omaha World-Herald. 5 May 1991.
16. ^ "Florida girl hiccuping again after returning to
school". msnbc.msn.com. March 16, 2007.
17. ^ ""Hiccup Girl" Jennifer Mee May Use Tourette's
Defense, Says Lawyer". CBS News. October 27, 2010.
18. ^ Symons, Jane (May 8, 2008). "So does holding your
breath REALLY banish hiccups?". London: The Sun.
Further reading
 Provine, Robert R. Curious Behavior: Yawning, Laughing,
Hiccupping, and Beyond (Harvard University Press; 2012) 246
pages; examines the evolutionary context for humans

13.  Shubin, Neil (February 2008). "Fish Out of Water". Natural
History: 26–31. – hiccup related to reflex in fish and amphibians.
External links
Look up hiccup in Wiktionary, the free dictionary.
 BBC News: Why we hiccup
 WIRED: The Best Cure for Hiccups: Remind Your Brain You’re Not
a Fish
 Cymet TC (June 2002). "Retrospective analysis of hiccups in
patients at a community hospital from 1995-2000". J Natl Med
Assoc 94 (6): 480–3. PMC 2594386. PMID 12078929.
[hide]
 v
 t
 e
Symptoms and signs: respiratory system (R04–R07, 786)
Hemorrhage
 Epistaxis
 Hemoptysis
Abnormalities
of breathing
Respiratory sounds
Stridor
Wheeze

14. Crackles
Rhonchi
Hamman's sign
Apnea
Dyspnea
Hyperventilation/Hypoventilation
Hyperpnea/Tachypnea/Hypopnea/Bradypnea
Orthopnea/Platypnea
Trepopnea
Biot's respiration
Cheyne-Stokes respiration
Kussmaul breathing
Hiccup
Mouth breathing/Snoring
Breath-holding
Other
 Asphyxia
 Cough
 Pleurisy
 Sputum

15.  Respiratory arrest
 Hypercapnia/Hypocapnia
 Pectoriloquy: Whispered pectoriloquy
 Egophony
 Bronchophony
 Pleural friction rub
 Fremitus
 Silhouette sign
Chest, general
 Chest pain
o Precordial catch syndrome
M: RES anat(n, x, l,
c)/phys/devp
proc,
drug(R1/2/3/5/6/7)