Nausea and vomiting are common symptoms that are associated with a variety of conditions (Mayo Clinic 2020).
What are Nausea and Vomiting?
It is important to note that nausea and vomiting are not conditions themselves - rather, they are non-specific symptoms (Cleveland Clinic 2019).
Nausea describes a feeling of unease in the stomach, chest or throat. Someone experiencing nausea will usually feel the urge to vomit, but vomiting will not necessarily occur.
Vomiting (emesis) is the physical act of forcibly ejecting stomach contents through the mouth. This may be a voluntary or involuntary action. Vomiting may occur independently of nausea.
(Cleveland Clinic 2019; Encyclopedia Britannica 2017; Shiel 2020)
Vomiting is a protective mechanism used to expel harmful substances in the stomach. It may also occur in response to irritation in the gut (NHS Inform 2020).
While nausea and vomiting may indicate a serious condition, they are not usually a cause for concern and generally resolve after one to two days (NHS Inform 2020).
Symptoms that are often associated with nausea and vomiting include:
Abdominal pain
Diarrhoea
Headache
Fever
Gas
Dizziness
Lightheadedness.
(Shiel 2020)
Acute nausea and vomiting generally describes symptoms that resolve within 48 hours. Nausea and vomiting that persists for over 48 hours may lead to complications or indicate a more serious illness (Knott 2020).
Abdominal pain and other symptoms may be associated with nausea and vomiting.
The Physiology of Vomiting
There are several sites involved in nausea and vomiting, in particular:
The chemoreceptor trigger zone (CTZ) , which is located in the brain near the vomiting centre in the medulla
The gastrointestinal tract
The vestibular system, which is responsible for balance, spatial orientation and movement
The higher centres in the cortex and thalamus.
(Athavale, Athavale & Roberts 2020; MacDougall & Sharma 2020)
These sites relay information to the vomiting centre, which is located in the medulla oblongata (part of the brain stem) and receives input from the nucleus tractus solitarius and vagus nerve. The vomiting centre is in charge of causing the vomiting reflex (MacDougall & Sharma 2020; Athavale, Athavale & Roberts 2020).
There are specific neurotransmitters that induce the action of vomiting. These include histamine, dopamine, serotonin, acetylcholine and neurokinin (Athavale, Athavale & Roberts 2020).
Prior to vomiting, the individual may display:
Nausea
Pallor
Cold sweat
Increased heart rate
Increased saliva production (to protect the teeth from stomach acid).
(Queensland Health 2018)
During the vomiting process, muscles in the diaphragm, chest wall and abdomen begin to contract, forcing the stomach contents upward. While this occurs, the epiglottis closes to ensure that the stomach contents cannot enter the trachea or lungs (Queensland Health 2018).
Causes of Nausea and Vomiting
There are many potential causes of nausea and vomiting, including:
Please note that this is not an exhaustive list of all potential causes.
Complications of Nausea and Vomiting
Rarely, nausea and vomiting may indicate a serious underlying condition such as appendicitis, meningitis, concussion or a brain tumour (Cleveland Clinic 2019).
If a client has had a fall or injury to the head, escalate care and call an ambulance.
Consult the client’s general practitioner if they are experiencing any of the following:
Vomiting that has persisted for longer than two days
Dehydration
Inability to keep down fluids for the past 12 hours
Green vomit (indicating the presence of bile)
Abdominal pain
Diabetes (as comorbidity).
(Healthdirect 2021a)
Seek emergency medical attention if a client is experiencing any of the following symptoms in addition to vomiting:
Chest pain
Severe abdominal pain or cramps
Blurry vision
Confusion
Stiff neck accompanied by a high fever
Faeces present in vomit
Rectal bleeding
Blood present in vomit (resembling coffee granules)
The best way to prevent nausea and vomiting is to maintain effective hygiene practices, as this will reduce the risk of spreading infections that cause these symptoms (Healthdirect 2021a).
Refer to the following articles for comprehensive information on maintaining effective hygiene:
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