Nausea and Vomiting


 * Associate Editor-In-Chief:

Synonyms and Keywords: emesis

Overview
Nausea (Latin: Nausea, Greek: , "sea-sickness") is the sensation of unease and discomfort in the stomach with an urge to vomit.

Nausea is not a sickness, but rather a symptom of several conditions, many of which are not related to the stomach. Nausea is often indicative of an underlying condition elsewhere in the body. Travel sickness, which is due to confusion between perceived movement and actual movement, is an example. The sense of equilibrium lies in the ear and works together with eyesight. When these two don't "agree" to what extent the body is actually moving the symptom is presented as nausea even though the stomach itself has nothing to do with the situation. Nausea is also an adverse effect of many drugs. Nausea may also be an effect of a large intake of sugary foods.

In medicine, nausea can be a problem during some chemotherapy regimens and following general anaesthesia. Nausea is also a common symptom of pregnancy. Mild nausea experienced during pregnancy can be normal, and should not be considered an immediate cause for alarm.
 * Vomiting  (also throwing up or emesis) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting may result from many causes, ranging from gastritis or poisoning to brain tumors, or elevated intracranial pressure (ICP). The feeling that one is about to vomit is called nausea. It usually precedes, but does not always lead to vomiting. Antiemetics are sometimes necessary to suppress nausea and vomiting, and in severe cases where dehydration develops, intravenous fluid may need to be administered to replace fluid volume.

The medical branch investigating vomiting, emetics and antiemetics is called emetology.

Complete Differential Diagnosis of the Causes of Nausea and Vomiting (alphabetical)

 * 1,2-Dichloroethene
 * 1,3-Dichloropropene
 * 2C-E
 * 2C-I
 * 2C-T-7
 * 2-Ethylhexanol
 * 5-Hydroxytryptophan
 * 5-MeO-AMT
 * Abrin
 * ABVD
 * Accessory pancreas
 * Acetaminophen (patient information)
 * Acetoxyketobemidone
 * Acetylcysteine
 * Achalasia
 * Aciclovir
 * Aconitine
 * Acoustic neuroma
 * Acromegaly
 * Acute Coronary Syndromes
 * Acute fatty liver of pregnancy
 * Acute HIV infection
 * Acute high altitude sickness
 * Acute pancreatitis
 * Acute prostatitis
 * Acute viral nasopharyngitis (common cold)
 * Adamsite
 * Addison's Disease
 * Adjustable gastric band
 * Adrenal failure
 * Afferent Loop Syndrome
 * Airsickness
 * Alatrofloxacin Injection (patient information)
 * Albuterol Inhalation (patient information)
 * Alcohol Withdrawal
 * Alcoholism
 * Aldesleukin (patient information)
 * Allylprodine
 * Alpha-Methyltryptamine
 * Alprazolam
 * Altitude sickness
 * Altretamine
 * Alvarado score
 * Amifostine
 * Amineptine
 * Aminocaproic acid
 * Aminopterin
 * Aminosalicylic acid
 * Amitriptyline (patient information)
 * Ammonium chloride
 * Amnesic shellfish poisoning
 * Amoxicillin
 * Amphotericin B
 * Amrinone
 * Amyl nitrite
 * Amyloidosis
 * Anadenanthera peregrina
 * Anastomosis stenosis
 * Anastrozole (patient information)
 * Anesthesia
 * Angina pectoris
 * Anorexia nervosa
 * Antihistamine
 * Antiretroviral drug
 * Anxiety
 * Aortic Arch Anomalies
 * Appendicitis
 * Arachnoid cyst
 * Aripiprazole (patient information)
 * Arsenic Poisoning
 * Asceptic Meningitis
 * Asparaginase (patient information)
 * Aspirin
 * Astrovirus
 * Atomoxetine
 * Auranofin
 * Autonomic neuropathy
 * Azithromycin
 * Aztreonam
 * Bacillus cereus
 * Balance disorder
 * Barbiturate
 * Barcoo Fever
 * Barium oxalate
 * Barium Sulfate (patient information)
 * Beef tapeworm
 * Beleric
 * Belladonna Alkaloid Combinations
 * Benign intracranial hypertension
 * Benzodiazepine
 * Benzylpiperazine
 * Beta-lactam antibiotic
 * Bevacizumab Injection (patient information)
 * Bezafibrate (patient information)
 * Bicalutamide (patient information)
 * Biliary colic
 * Blastocystosis
 * Bleomycin
 * Bortezomib
 * Bowel obstruction
 * Brain Stem Gliomas
 * Brain tumor
 * Breastfeeding complications
 * Bromelain
 * Bromomethane
 * Bronchodilator
 * Brucella
 * Bulimia nervosa
 * Buprenorphine
 * Bupropion
 * Busulfan (patient information)
 * Butanethiol
 * Butorphanol
 * Cabergoline
 * Caecitis
 * Calcitonin
 * Calcitriol
 * Calcium carbamide
 * Cancer
 * Capecitabine (patient information)
 * Capsaicin
 * Carbon monoxide poisoning
 * Carboplatin (patient information)
 * Cardiac arrhythmia
 * Carmustine (patient information)
 * Carprofen
 * Carvedilol (patient information)
 * Caspofungin
 * Cefaclor
 * Cefoperazone Sodium Injection (patient information)
 * Cefuroxime
 * Cephalosporin
 * Cerebral aneurysm
 * Cerebral arteriovenous malformation
 * Cerebral hemorrhage
 * Cerebral shunt (blocked)
 * Cerebrovascular disease
 * Cetuximab Injection (patient information)
 * Cevimeline
 * Chelation therapy
 * Chemotherapy
 * Childbirth
 * Chloral hydrate
 * Chlordiazepoxide
 * Chloromethane
 * Chlorothiazide
 * Chlorpropamide
 * Cholecystitis
 * Cholecystolithiasis
 * CHOP
 * Chronic fatigue syndrome
 * Cicuta
 * Ciguatera
 * Cimicifuga racemosa
 * Cinchonism
 * Cisplatin
 * Citalopram
 * Cladribine (patient information)
 * Clarithromycin
 * Clindamycin
 * Clofarabine
 * Clofibrate
 * Clomifene
 * Clorazepate
 * Co-codamol
 * Codeine
 * Colorado tick fever
 * Combat stress reaction
 * Community-acquired pneumonia
 * Concussion
 * Contraceptive patch
 * Coprinopsis atramentaria
 * Craniopharyngioma
 * Crohn's disease
 * Croup
 * Cryptosporidium parvum
 * Cyanogen
 * Cyclic vomiting syndrome
 * Cyclophosphamide
 * Cyclospora cayetanensis
 * Cytarabine (patient information)
 * Cytisine
 * Dacarbazine (patient information)
 * Dactinomycin (patient information)


 * Dantrolene
 * Daptomycin
 * Darbepoetin Alfa Injection (patient information)
 * Darunavir (patient information)
 * Daunorubicin (patient information)
 * Decompression sickness
 * Deferasirox (patient information)
 * Defibrotide
 * Dehydration
 * Dengue fever
 * Depression
 * Dextroamphetamine and Amphetamine (patient information)
 * Dextromethorphan
 * Dextropropoxyphene
 * Diabetes mellitus
 * Diabetic gastroparesis
 * Diabetic Ketoacidosis
 * Diarrheal shellfish poisoning
 * Diazepam
 * Diazinon
 * Dicofol
 * Dientamoebiasis
 * Diethyl ether
 * Diethylcathinone
 * Diflunisal
 * Digitalis purpurea
 * Digitoxin
 * Digoxin
 * Dioxathion
 * Dioxin
 * Diphtheria
 * Disagreeable sights, smells or thoughts (such as decayed matter, others' vomit, thinking of vomiting), etc.
 * Disulfiram
 * Diuretic
 * Diverticulitis
 * Docetaxel (patient information)
 * Dofetilide (patient information)
 * Dolasetron (patient information)
 * Donepezil (patient information)
 * Dosulepin hydrochloride
 * Doxorubicin
 * DTPA
 * Duke's disease
 * Duloxetine
 * Dumping syndrome
 * Ear infection
 * Ebola
 * Emergency contraception
 * Emetine
 * Encephalitis
 * Endometriosis
 * Endosulfan
 * Enfuvirtide
 * Entecavir (patient information)
 * Enteric Neuropathy
 * Eosinophilic gastroenteritis
 * Ependymoma
 * Epiploic appendagitis
 * Epirubicin Injection (patient information)
 * Episodic ataxia
 * Epistaxis
 * Epoetin Alfa Injection (patient information)
 * Ergotism
 * Erlotinib (patient information)
 * Erotic vomiting
 * Erythromycin
 * Esophageal cancer
 * Esophageal diverticulum
 * Esophageal stenosis
 * Esophagitis
 * Essure
 * Estradiol
 * Estrogen and Progestin (Oral Contraceptives) (patient information)
 * Ethcathinone
 * Ethchlorvynol
 * Ethosuximide
 * Ethyl carbamate
 * Ethylmorphine
 * Etidronate (patient information)
 * Etoposide
 * Exenatide
 * Exercise induced nausea
 * Exercise urticaria
 * Extreme pain
 * Familial hemiplegic migraine
 * Felbamate (patient information)
 * Fentanyl Oral Transmucosal (patient information)
 * Fexofenadine
 * Filgrastim (patient information)
 * Fioricet
 * Floxuridine (patient information)
 * Flu
 * Fluconazole
 * Flucytosine
 * Fludarabine Phosphate (patient information)
 * Fluorescein
 * Fluoride poisoning
 * Fluorouracil (patient information)
 * Flurazepam
 * Flutamide (patient information)
 * Food allergies
 * Food poisoning
 * Foreign bodies
 * Fructose intolerance hypoglycemia
 * Fulvestrant Injection (patient information)
 * Fundic gland polyposis
 * Gabapentin (patient information)
 * Gamma-Hydroxybutyric acid
 * Gastric carcinoma
 * Gastric outlet obstruction
 * Gastritis
 * Gastrocolic fistula
 * Gastroenteritis
 * Gastroesophageal reflux disease
 * Gastrointestinal perforation
 * Gastroparesis
 * Gatifloxacin (patient information)
 * Gefitinib (patient information)
 * Gemcitabine Hydrochloride (patient information)
 * Gemeprost
 * General anaesthesia
 * Gestational diabetes
 * Giardia lamblia
 * Ginger
 * Ginkgo
 * Glaucoma
 * Glioblastoma multiforme
 * Glioma
 * Glycylcycline
 * Goserelin (patient information)
 * Graft-versus-host disease
 * Granisetron (patient information)
 * Green Tobacco Sickness
 * Grifulvin V
 * Guaifenesin
 * Hangover
 * Hantavirus pulmonary syndrome
 * Head trauma
 * Heat stroke
 * Heavy metal ingestion
 * Helicobacter pylori infection
 * HELLP syndrome
 * Hemicrania continua
 * Hemorrhage
 * Henipavirus
 * Hepatic coma
 * Hepatic porphyria
 * Hepatitis B
 * Hepatitis D
 * Hepatitis E
 * Herkinorin
 * Hernia
 * Heroin
 * HIV
 * Hookworm
 * Hormone replacement therapy (trans)
 * Human ehrlichiosis
 * Hydralazine
 * Hydrocephalus
 * Hydrochlorothiazide
 * Hydrocodone
 * Hydromorphone
 * Hydroxychloroquine
 * Hydroxyurea (patient information)
 * Hydroxyzine (patient information)
 * Hypercalcemia
 * Hyperemesis gravidarum
 * Hypermagnesemia
 * Hyperparathyroidism
 * Hypertension
 * Hyperthermia
 * Hyperthyroidism
 * Hypervitaminosis A
 * Hypocalcemia
 * Hypocholermia
 * Hypoglycemia
 * Hypokalemia
 * Hyponatremia
 * Hysterical contagion
 * Iatrogenesis
 * Ibogaine


 * Ibuprofen
 * Idarubicin (patient information)
 * Idiopathic
 * Ifosfamide (patient information)
 * Ileus
 * Imatinib (patient information)
 * Imipenem
 * Inappetence
 * Indometacin
 * Inflammation in the area of the vestibular organ
 * Influenza
 * Instillation abortion
 * Interstitial nephritis
 * Intestinal parasite
 * Intussusception (medical disorder)
 * Iodomethane
 * Iron(II) sulfate
 * Irritable bowel syndrome
 * Irukandji syndrome
 * Ischemic bowel
 * Isoniazid
 * Isopropyl alcohol
 * Isosorbide mononitrate
 * Itraconazole
 * Kaopectate
 * Kaposi's sarcoma
 * Ketogenic diet
 * Ketorolac
 * Ketotic hypoglycemia
 * La Crosse encephalitis
 * Labyrinthitis
 * Lactose intolerance
 * Lanreotide
 * Lassa fever
 * Lead poisoning
 * Letrozole (patient information)
 * Leuprolide (patient information)
 * Levodopa and Carbidopa (patient information)
 * Lewisite
 * Lindane
 * Listeria monocytogenes
 * Lithium nitrate
 * Lobelia
 * Lomotil
 * Lopinavir
 * Loprazolam
 * Lorazepam
 * Lower respiratory tract infection
 * Malaria
 * Malaria prophylaxis
 * Marine toxins
 * Mastocytosis
 * Mazindol
 * Mechlorethamine (patient information)
 * Medazepam
 * Medical cannabis
 * Megestrol (patient information)
 * Melarsoprol
 * Melphalan (patient information)
 * Ménière's disease
 * Meningitis
 * Meningococcemia
 * Meningoencephalitis
 * Mercaptopurine
 * Meropenem
 * Mesalamine (patient information)
 * Mescaline
 * Mesenteric infarction
 * Mesna (patient information)
 * Metabolic acidosis
 * Metal fume fever
 * Metformin
 * Methadone
 * Methotrexate
 * Methylergonovine
 * Methylketobemidone
 * Methylphenidate
 * Methyprylon
 * Metronidazole
 * Mifepristone
 * Migraine
 * Milk of Magnesia
 * Miltefosine
 * Minimally Invasive Thorasic Spinal Fusion
 * Mirtazapine
 * Misoprostol
 * Mitomycin (patient information)
 * Mitotane
 * Mitoxantrone
 * Moclobemide
 * Monocrotophos
 * Mood stabilizer
 * MOPP (medicine)
 * Morning sickness
 * Morphine
 * Motion sickness
 * Motofen
 * Moxifloxacin
 * Multiple chemical sensitivity
 * Murray Valley encephalitis virus
 * Mushroom poisoning
 * Mycophenolic acid
 * Myocardial infarction
 * Nabilone
 * Naegleria fowleri
 * Nafcillin
 * Nalbuphine
 * Nalmefene
 * Naloxone
 * Naphthalene
 * Natamycin
 * Nerve agent
 * Nervousness
 * N-Ethyl-3-piperidyl benzilate
 * Nicorandil
 * Nicotine poisoning
 * Nilutamide (patient information)
 * Nitrazepam
 * N-Nitroso-N-Methylurea
 * Non-Hodgkin lymphoma
 * Nootropic
 * Norovirus
 * Norplant
 * Nortriptyline (patient information)
 * Norwalk Virus
 * Nutcracker syndrome
 * Obidoxime
 * Olanzapine (patient information)
 * Omeprazole (patient information)
 * Ondansetron
 * Opioid
 * Orellanine
 * Orthostatic reaction
 * Oseltamivir (patient information)
 * Osteosarcoma
 * Otitis interna
 * Ovarian cyst
 * Ovarian hyperstimulation syndrome
 * Ovarian torsion
 * Oxaliplatin
 * Oxamniquine
 * Oxazepam
 * Oxcarbazepine
 * Oxybutynin (patient information)
 * Oxycodone and aspirin (patient information)
 * Paclitaxel
 * Paliperidone (patient information)
 * Palonosetron
 * Panic attack
 * Pegaspargase (patient information)
 * Pemetrexed injection (patient information)
 * Penicillin
 * Pentamidine
 * Pentavalent antimonial
 * Pentetic acid
 * Pentostatin (patient information)
 * Peptic ulcer
 * Pergolide (patient information)
 * Perhexiline
 * Peritonitis
 * Pesticide
 * Pfiesteria piscicida
 * PFPP
 * Phenelzine (patient information)
 * Phentermine
 * Pholcodine
 * Phytohaemagglutinin
 * Pioglitazone (patient information)
 * Piribedil
 * Plicamycin (patient information)
 * PMA
 * Pneumonia
 * Polio
 * Poliomyelitis
 * Porphyria
 * Posaconazole (patient information)
 * Post-concussion syndrome
 * Post-exposure prophylaxis
 * Postoperative nausea and vomiting
 * Postoperative pain
 * Post-tussive emesis
 * Potassium bromide
 * Potassium chloride
 * Praziquantel
 * Pregabalin (patient information)


 * Pregnancy
 * Primaquine (patient information)
 * Procainamide (patient information)
 * Procarbazine (patient information)
 * Prochlorperazine
 * Prolactinoma
 * Propiram
 * Propylketobemidone
 * Prosidol
 * Protriptyline (patient information)
 * Pseudo-obstruction
 * Psychogenic vomiting
 * Pulmonary embolism
 * Pyelonephritis
 * Pyloric stenosis
 * Pyrazinamide
 * Pyridoxine deficiency
 * Q fever
 * Quetiapine (patient information)
 * Quinupristin/dalfopristin
 * Radiation poisoning
 * Ranolazine (patient information)
 * Rasagiline (patient information)
 * Refractive error
 * Renal colic
 * Renal failure
 * Reserpine
 * Reye's syndrome
 * Risedronate (patient information)
 * Rituximab injection (patient information)
 * Rivastigmine (patient information)
 * Rizatriptan (patient information)
 * Rocky Mountain spotted fever
 * Ropinirole (patient information)
 * Rotigotine
 * Roxithromycin
 * Rubbing alcohol
 * Salpingitis
 * Salsalate (patient information)
 * Sarin
 * Sativex
 * Scarlet fever
 * Scleroderma
 * Seasickness
 * Secobarbital
 * Selective serotonin reuptake inhibitor
 * Selegiline (patient information)
 * Seliciclib
 * Sexual fetish (emetophilia)
 * Shigella
 * Sibutramine (patient information)
 * Ski sickness
 * Sleep deprivation
 * Slone's Disease
 * Small bowel bacterial overgrowth syndrome
 * Small intestine cancer
 * Smoke inhalation
 * Snakebites
 * Soapwort
 * Sodium polystyrene sulfonate (patient information)
 * Sodium stibogluconate
 * Solanine
 * Sorafenib (patient information)
 * Spider bite
 * Spironolactone (patient information)
 * Splenic infarction
 * Spoiled foods
 * Sporotrichosis
 * Spotted fever
 * SSRI discontinuation syndrome
 * Staphylococcal enteritis
 * Stiripentol
 * Strep throat
 * Streptozocin (patient information)
 * Subdural hematoma
 * Sufentanil
 * Sultiame
 * Sumatriptan injection (patient information)
 * Sunitinib (patient information)
 * Suramin
 * Syndrome of inappropriate antidiuretic hormone (SIADH)
 * Tabes dorsalis
 * Tacrine
 * Tapentadol
 * Telbivudine (patient information)
 * Telithromycin (patient information)
 * Temik
 * Temozolomide
 * Teniposide (patient information)
 * Testicular rupture
 * Testicular torsion
 * Tetanus, Diphtheria, and Pertussis (Tdap) Vaccine (patient information)
 * Tetrahydrocannabinol
 * Tetrahydrozoline
 * Tetramethylsuccinonitrile
 * Tetrodotoxin
 * Theobromine
 * Thiabendazole
 * Thiethylperazine
 * Thioguanine (patient information)
 * Thiotepa (patient information)
 * Thrombotic thrombocytopenic purpura
 * Thyroid Medication (patient information)
 * Thyrotoxicosis
 * Tigecycline
 * Tobacco smoking and second-hand smoke
 * Tocopherol
 * Tolmetin
 * Topiramate
 * Topotecan Hydrochloride (patient information)
 * Toxidrome
 * Tralomethrin
 * Tramadol
 * Trandolapril
 * Trastuzumab
 * Traumatic brain injury
 * Traveler's diarrhea
 * Trazodone
 * Triamterene
 * Triazolam
 * Triclofos
 * Tricyclic antidepressant
 * Trifluoperazine
 * Trifluoromethylphenylpiperazine
 * Trimeperidine
 * Trimethobenzamide (patient information)
 * Trimetrexate Glucuronate (patient information)
 * Tropisetron
 * Trovafloxacin (patient information)
 * Tularemia
 * Twisted ovarian cyst
 * Typhoid Vaccine (patient information)
 * Typhus
 * Ulcers
 * Uremia
 * Urofollitropin
 * Urolithiasis
 * Vagotomy
 * Valaciclovir
 * Valproic Acid (patient information)
 * Varenicline
 * Vasovagal syncope
 * Venlafaxine
 * Vertebro-basilar syndrome
 * Vertigo
 * Vestibular balance disorder
 * Vestibular neuronitis
 * Vibrio parahaemolyticus
 * Vicodin
 * Vidarabine
 * Vigabatrin
 * Viloxazine
 * Vinblastine (patient information)
 * Vinorelbine Tartrate (patient information)
 * Violent emotions (including laughing)
 * Violent fits of coughing or hiccups
 * Vitamin A
 * Vitamin C
 * Vitamin D
 * Volvulus
 * Voriconazole
 * Vorinostat (patient information)
 * Water intoxication
 * Waterborne diseases
 * West Nile virus
 * Yellow fever
 * Zanamivir Inhalation (patient information)
 * Ziprasidone (patient information)
 * Zollinger-Ellison Syndrome
 * Zolpidem (patient information)
 * Zopiclone

Vomiting center
Vomiting is coordinated in the vomiting center in the lateral medullary reticular formation in the pons. Receptors on the floor of the fourth ventricle of the brain represent a chemoreceptor trigger zone, stimulation of which can lead to vomiting. The chemoreceptor zone lies outside the blood-brain barrier, and can therefore be stimulated by blood-borne drugs that can stimulate vomiting, or inhibit it.

There are various sources of input to the vomiting center:
 * The chemoreceptor trigger zone at the base of the fourth ventricle has numerous dopamine D2 receptors, serotonin 5-HT3 receptors, opioid receptors, Acetylcholine receptors, and receptors for substance P. Stimulation of different receptors are involved in different pathways leading to emesis, in the final common pathway substance P appears to be involved.
 * The vestibular system which sends information to the brain via cranial nerve VIII (vestibulocochlear nerve). It plays a major role in motion sickness and is rich in muscarinic receptors and histamine H1 receptors.
 * Cranial nerve X (vagus nerve), which is activated when the pharynx is irritated, leading to a gag reflex.
 * Vagal and enteric nervous system inputs that transmit information regarding the state of the gastrointestinal system. Irritation of the GI mucosa by chemotherapy, radiation, distention or acute infectious gastroenteritis activates the 5-HT3 receptors of these inputs.
 * The CNS mediates vomiting arising from psychiatric disorders and stress.

Vomiting Act
The vomiting act encompasses three types of outputs initiated by the medulla: Motor, parasympathetic nervous system (PNS) and sympathetic nervous system (SNS). Collectively, they are as follows:


 * Increased salivation to protect the enamel of teeth from stomach acids (excessive vomiting leads to caries). This is part of the PNS output.
 * Retroperistalsis, starting from the middle of the small intestine, sweeping up the contents of the digestive tract into the stomach, through the relaxed pyloric sphincter.
 * A lowering of intrathoracic pressure (by inspiration against a closed glottis), coupled with an increase in abdominal pressure as the abdominal muscles contract, propels stomach contents into the esophagus without involvement of retroperistalsis. The lower esophageal sphincter relaxes. This is part of the motor output, and it is also important to note that the stomach itself does not contract in the process of vomiting.
 * Vomiting is ordinarily preceded by retching.
 * Vomiting also initiates a SNS response causing both sweating and increased heart rate.

The neurotransmitters that regulate vomiting are poorly understood, but inhibitors of dopamine, histamine and serotonin are all used to suppress vomiting, suggesting that these play a role in the initiation or maintenance of a vomiting cycle. Vasopressin and neurokinin may also participate.

Content
Since the stomach secretes acid, vomit contains a high concentration of hydronium ions and is thus strongly acidic. Recent food intake will be reflected in the gastric vomit.

The content of the vomitus (vomit) may be of medical interest. Fresh blood in the vomit is termed hematemesis ("blood vomiting"). Old blood bears resemblance to coffee grounds (as the iron in the blood is oxidized), and when this matter is identified the term "coffee ground vomiting" is used. Bile can enter the vomit during subsequent heaves due to duodenal contraction if the vomiting is severe. Fecal vomiting is often a consequence of intestinal obstruction, and is treated as a warning sign of this potentially serious problem ("signum mali ominis"); such vomiting is sometimes called "miserere". If food has recently been consumed, then partly digested food may show up in the vomit.

If the vomiting reflex continues for an extended period of time with no appreciable vomitus, the condition is known as non-productive emesis or dry heaves, which can become both extremely painful and debilitating.

Physical Examination

 * Exams should include:
 * Neurologic
 * Ear
 * Ophthalmagic
 * Abdominal

Laboratory Findings

 * Complete blood count (CBC)
 * Electrolytes
 * Liver function tests (LFTs)
 * Amylase
 * Lipase
 * Calcium
 * Magnesium
 * Salicylate level
 * Hepatitis serologies
 * Cerebrospinal fluid (CSF) analysis
 * Toxicology screen

Electrolyte and Biomarker Studies

 * Electrolytes

Electrocardiogram

 * ECG to rule out an inferior MI or arrhythmia

X Ray

 * Plain kidney, ureter, bladder (KUB) X-rays

MRI and CT

 * Abdominal CT scan (with oral and IV contrast)
 * Head CT scan

Echocardiography or Ultrasound

 * Abdominal/pelvic ultrasound

Other Diagnostic Studies

 * Endoscopy
 * Colonoscopy

Treatment

 * Fluid resuscitation (due to vomiting-induced dehydration)
 * Treat underlying disease etiologies

Treatment of Nausea
While short-term nausea and vomiting are generally harmless, they may sometimes indicate a more serious condition, such as Coeliac disease. When associated with prolonged vomiting, it may lead to dehydration and/or dangerous electrolyte imbalances.

Symptomatic treatment for nausea and vomiting may include short-term avoidance of solid food. This is usually easy as nausea is nearly always associated with loss of appetite. Dehydration may require rehydration with oral or intravenous electrolyte solutions. If the cause is by motion sickness, sitting down in a still environment may also help.

There are several types of antiemetics, and researchers continue to look for more effective treatments. The main types used post operatively for surgical patients are ondansetron, dexamethasone, promethazine, diphenhydramine, and in small doses droperidol. Doxylamine is the drug of choice in pregnancy-related nausea. Anecdotally, another remedy used by recovery room nurses is to place an isopropyl alcohol swab under the patient's nose while he or she breathes through the nose. This may abate the nausea until the antiemetic medication takes effect. When ingested or inhaled, the chemical compound tetrahydrocannabinol has been shown to reduce nausea in some users. Also available are a variety of non-invasive (often untested) mechanical devices used to suppress nausea due to motion sickness.

The spice ginger is also used for centuries as a folk remedy to treat nausea, and recent research has supported this use.

Acute Pharmacotherapies

 * Antiemetics: An antiemetic is a drug that is effective against vomiting and nausea. Antiemetics are typically used to treat motion sickness and the side effects of some opioid analgesics and chemotherapy directed against cancer. Antiemetics act by inhibiting the receptor sites associated with emesis. Hence, anticholinergics, antihistamines, dopamine antagonists, serotonin antagonists and cannabinoids are used as anti-emetics.
 * Anticholinergics

Surgery and Device Based Therapy

 * Colonoscopy/endoscopy may also be used as therapy

Aspiration of vomit
Vomiting can be very dangerous if the gastric content gets into the respiratory tract. Under normal circumstances the gag reflex and coughing will prevent this from occurring, however these protective reflexes are compromised in persons under narcotic influences such as alcohol or anesthesia. The individual may choke and asphyxiate or suffer an aspiration pneumonia.

Dehydration and electrolyte imbalance
Prolonged and excessive vomiting will deplete the body of water (dehydration) and may alter the electrolyte status. The loss of acids leads to metabolic alkalosis (increased blood pH), and the electrolyte imbalance shows hypokalemia (potassium depletion) and hypochloremia (chlorine depletion). The hypokalemia is an indirect result of the kidney compensating for the loss of acid. With the loss of intake of food the individual will become cachectic.