Nausea

Nausea is experienced by over 50% of adults who have experienced at least one bout of nausea, and over 30% have experienced at least one episode of vomiting. Nausea was more common in women than in men. Nausea is the sensation to vomit out the contents due to multiple reasons like gastrointestinal issues, morning sickness, motion sickness, food poisoning, migraine and many others. This overview will help you to go through the nausea's definition, its types, management, diagnosis, key facts, and other crucial aspects of the condition, equipping readers with the insights needed to comprehend and curb the management of this condition (Singh et al., 2015).

What is nausea? 

Nausea is a feeling of getting a stronger urge to vomit and stomach queasiness (Nausea and Vomiting – Adults: MedlinePlus Medical Encyclopedia, n.d.). It is a sign indicating disturbance in the body's gastrointestinal, central nervous, or vestibular systems rather than a distinct illness. It is usually linked with diseases of the inner ear, brain, digestive tract, or even systemic diseases, including infections or metabolic abnormalities. 

With the brainstem, especially the chemoreceptor trigger zone (CTZ), playing a prominent part, nausea results from intricate interactions between the gut and brain. It can be acute or chronic; in some circumstances, anticipatory (Zhong et al., 2021). 

The most often impacted organs are the stomach, intestines, and regions of the brain in charge of vomiting control. Left untreated, nausea might cause dehydration, electrolyte imbalance, malnutrition, or weight loss. Though not infectious or communicable, nausea could be a sign of infections like gastroenteritis. It is manageable and sometimes curable depending on the cause (Zhong et al., 2021).  

• Pregnancy: 70-80% of pregnant women suffer from morning sickness, usually peaking in the first trimester but sometimes continuing throughout pregnancy. Hormonal changes, especially increased progesterone and oestrogen, can disrupt gastric motility, therefore contributing to nausea and vomiting in pregnancy (NVP) (Liu et al., 2022).  
• Motion Sickness: Arises when visual and proprioceptive signals clash with vestibular input from the inner ear, thus generating a sensory discrepancy that causes nausea and vomiting. The brainstem's emetic centre is triggered via vestibular nuclei and cerebellum by this sensory conflict, therefore causing the usual motion-induced sickness reaction (American Academy of Family Physicians, 2014).
• Infections: Gastroenteritis, caused by viruses or bacteria, inflames the gastrointestinal tract and provokes vomiting via signal stimulation. Direct gastrointestinal irritation and reflex vomiting are caused by food poisoning, especially resulting from toxins (Zhong et al., 2021).
• Migraines: Migraines frequently involve nausea and vomiting, driven by activation of central chemoreceptors and brainstem structures during migraine attacks (Ruschel & De Jesus, 2024). 
• Digestive Disorders: GERD causes nausea by stimulating vagal routes and irritating the oesophagus. Toxin-induced irritation of the stomach/intestine leads to vomiting during food poisoning. Often, diabetes, gastroparesis, and delayed stomach emptying cause fullness, bloating, and ongoing vomiting. Mechanical obstruction stops contents from passing and triggers strong vomiting reflexes through visceral afferents (Zhong et al., 2021).
• Drugs and Therapies: Chemotherapy-induced nausea and vomiting (CINV) are divided into forms like acute (<= 24 h), delayed (>= 24 h), breakthrough, anticipatory, and refractory. Among other antiemetic-precipitating drugs are anaesthetics, narcotics, antibiotics, and metformin (Zhong et al., 2021).  
• Emotional and Sensory Triggers: Anxiety and tension may activate the limbic system and the vomiting centre, therefore producing retching in sensitive people. Via central routes, vomiting can be induced by strong smells or flavours sensed as unpleasant or nauseating (Symptoms & Causes of Cyclic Vomiting Syndrome, 2025).  
• Chronic Nausea Syndrome: Long-term, disabling nausea and vomiting can be brought on by illnesses including chronic gastritis, peptic ulcers, and chronic gastroparesis (Lacy et al., 2018). 

Early indicators of typically preceding full-blown nausea are:

• Uneasiness
• An ambiguous sense of stomach pain
• Lightheadedness or fainting
• If not treated, these symptoms may advance to nausea or vomiting.

Nausea is often accompanied by other symptoms (Symptoms, 2017), depending on the underlying conditions: 

• Vomiting 
• Abdominal pain or cramping 
• Bloating 
• Indigestion 
• Fatigue or general discomfort 
• Dizziness or vertigo 
• Sweating 
• Increased heart rate 
• Loss of appetite 
• Excess saliva or dry mouth 

In instances when food poisoning occurs, vomiting could be accompanied by diarrhoea and fever. Headache, photophobia, or disorientation are commonly associated with migraines, which involve nausea and vomiting.

• Prodromal Phase: Before vomiting, there often is a warning period spanning minutes to hours. Common symptoms are nausea, more salivation, pallor, sweating, abdominal pain, lethargy, irritability, insomnia, and sporadic temperature fluctuations. Autonomic symptoms, including heart rate changes and vasopressin release, may also appear during this stage, pointing to a developing defence mechanism (Hasler, 2022).
• The Phase of Vomiting or Retching (Emetic): Distinguished by severe nausea and constant retching resulting in strong vomiting. Patients with conditions like cyclic vomiting syndrome could have 1 to 6 episodes an hour; vomiting could involve bile and be accompanied by abdominal pain, pallor, listlessness, headache, photophobia, and sometimes fever or hypothermia (Ferguson, 1988).  
• Phase of recovery (post-emetic): Vomiting stops, and the patient usually feels exhausted. Nausea, anorexia, retching, and abdominal discomfort all subside gradually. Sleep and relaxation are usual throughout this period since it helps the body to recover (Nausea and Vomiting | EBSCO, n.d.).

Several factors (Zhong et al., 2021) cause nausea, including central (brain-related) or peripheral (gut-related):

• Gastrointestinal Causes: Gastritis, gastroenteritis, ulcers, gastroparesis
• Neurological Causes: Head injury, migraine, elevated intracranial pressure
• Vestibular Causes: Vertigo and motion sickness. 
• Metabolic and Endocrine Causes: Pregnancy, uremia, diabetic ketoacidosis 
• Drug-induced: Opioids, anaesthesia, antibiotics, chemotherapy
• Psychological: Anxiety, eating disorders, stress
• Viral Illness: While nausea itself is not infectious, some viral illnesses like norovirus or rotavirus might cause nausea as part of gastroenteritis. 

People who are probably to get nausea include:

• Persons with a history of motion sickness.
• Those receiving radiation or chemotherapy.
• Pregnant women (particularly in the first trimester).
• People who suffer from migraines or vestibular diseases.
• Suffering from persistent digestive issues.
• People use antibiotics, painkillers, or anti-inflammatory drugs.
• People suffering from anxiety or stress-related illnesses.

Who is at risk? 

The individuals prone to risk are pregnant women; patients with chronic kidney, liver or GI conditions; cancer patients undergoing treatment and radiation therapy; post-surgery individuals with a history of migraines or vertigo; and those who are under stress and anxiety (Singh et al., 2015). 

Early treatment is underlined by the fact that these problems might manifest themselves within days of ongoing symptoms. However, untreated or chronic nausea and vomiting can cause major health problems (Heckroth et al., 2021): 

• Dehydration: Frequent vomiting and decreased fluid intake. This results in dry mouth, sunken eyes, vertigo, weariness, and, in extreme cases, kidney failure.  
• Electrolyte Imbalance: Chronic vomiting leads to the loss of electrolytes and gastric acids, namely sodium (Na⁺), potassium (K⁺), and chloride (Cl⁻). This can result in hypokalaemia and hypochloraemic metabolic alkalosis, which causes muscle cramps, arrhythmias, and neurological symptoms. 
• Malnutrition and Weight Reduction: Persistent nausea usually curbs hunger and nutrient intake, leading to undernutrition. Among hospitalised patients, malnutrition raises mortality rates, compromises immunological capacity, and disrupts gut function.  
• Fatigue and Weakness: Nutritional and fluid loss lower energy levels, which causes extreme tiredness and an inability to complete normal activities.
• Pneumonia and aspiration: Forceful vomiting can cause inhalation of vomit into the lungs, which results in aspiration pneumonia, a potentially fatal illness, especially in unconscious or dysphagic persons.  
• Dental harm and Oesophagus Tears: Mallory-Weiss tears in the oesophagus brought on by continuous vomiting can lead to excruciating haemorrhage. Frequent vomiting also exposes teeth to stomach acid, stripping enamel and leading to dental decay.
• Reduced Quality of Life: Chronic nausea limits diet, social interactions, and work output, therefore generating psychological discomfort. Effective antiemetic treatment boosts quality of life by avoiding such problems.  

Preventive measures (Brainard & Gresham, 2014) depend on the underlying causes and can considerably lessen symptom intensity and frequency:

• Motion Sickness: An hour before travelling, eat modest, high-carbohydrate, low-fat food. Stay hydrated and refrain from caffeine or alcohol. Concentrate on the horizon, settle in less turbulent sections of cars, reduce head movement, and guarantee fresh air. Take antiemetics, though sedation might happen; scopolamine patches or antihistamines like meclizine could prove helpful.  
• Dietary Strategy: Avoid strong-smelling, spicy, or oily foods; instead, consume little, regular, mild meals (e.g., crackers, rice, bananas). Reduce stomach overload and nausea by drinking liquids between meals rather than with food. Start with little sips of plain liquids (water, ginger ale) and move to electrolyte-rich beverages when tolerated. Take light foods. 
• Electrolytes and Hydration: Stay hydrated with little and constant sips. Monitor fluid output and check for dehydration symptoms, very dark urine, sunken eyes, and dry mouth.  
• Lifestyle and Environmental Measurements: Stay clear of powerful scents and spoilt or foreign cuisine. Remain in well-ventilated, cool surroundings to help relieve sickness. Rest enough after meals. Controlled breathing or mindfulness helps you to control stress, which is especially useful for psychogenic nausea. 
• Prenatal Care: Start early prenatal visits to control nausea brought on by pregnancy. Early-morning nausea can be reduced by nutritional advice, including vitamin B₆ and maybe ginger.
• Stress Management: Practice mindful exercise and relaxation techniques to keep away from stress and anxiety. 
• Medication Strategies: Proactive antiemetic medication (ondansetron, metoclopramide, scopolamine patches) can successfully stop nausea in high-risk situations like chemotherapy, anaesthesia, and pregnancy. 

Diagnosis and tests for nausea (Davis & Bryant, 2023) includes the following strategies:

Physical Examination and Clinical History: 

• Often, the cause can be found by means of a thorough history (onset, duration, triggers, accompanying symptoms) and examination looking for dehydration, abdominal sensitivity, neurologic symptoms, or vestibular dysfunction.

Laboratory Examination: 

• Blood Test: An evaluation for infection or anaemia is the complete blood count. 
• Electrolytes and Metabolic Panel: Detects dehydration-related imbalances, such as hypokalaemia or alkalosis. 
• Test Liver and Kidney Function: Find causes of hepatic or renal illness.  
• Amylase/Lipase: Assists in the diagnosis of pancreatitis. 
• Albumin/Nutritional Indicators: Show undernutrition stemming from ongoing symptoms.
• Pregnancy Test: For women of childbearing age, it is compulsory.

Imaging:  

• CT or Abdominal Ultrasound: Tumours, inflammation, gallstones or obstructions.   Needed if there are neurological signs (e.g., increased intracranial pressure).
• MRI/CT Brain: Required for neurological signs. 

Endoscopy: 

• Direct visualisation and biopsy of the oesophagus, stomach, and duodenum, useful for ulcers, gastritis, or malignancy. 

Motility and Vestibular Testing: 

• SmartPill or Gastric Emptying Scintigraphy: Identify gastroparesis. 
• Endo-/Gastric Or Oesophageal Manometry: Checks gastrointestinal motility. 
• Vestibular Function Testing: For vertigo-induced nausea.

Differential Diagnosis: Clinicians must differentiate between intersecting causes. Food poisoning versus gastroenteritis, pregnancy versus gastric ulcer, migraine versus vestibular neuritis, and medication side effects versus central neurological cause. 

Medical care is advised if a person is feverish, weak, and vomiting more than twice a day; has stomach discomfort; is unable to retain any liquids; has symptoms that last more than two days; or has not urinated in more than eight hours. Effective management complements (Hauser et al., 2022)  (Heckroth et al., 2021b) the underlying aetiology and symptom severity:

Rehydration: 

Oral electrolyte solutions are preferred if dehydration results from fluid loss from severe vomiting. Intravenous rehydration may be necessary if this is ineffective or impractical.  

General Drugs: 

• Antihistamines and anticholinergics like meclizine and scopolamine are especially successful for those who experience motion sickness and vertigo (Takov & Tadi, 2023b).
• Dopamine antagonists like metoclopramide, prochlorperazine, and chlorpromazine are the most effective treatments for the nausea and vomiting that accompany migraine headaches (Lew & Punnapuzha, 2023).
• Serotonin antagonists like ondansetron have been shown to decrease the need for intravenous fluid resuscitation as well as to suppress nausea and vomiting in cases of gastroenteritis (Griddine & Bush, 2023).
• The first-line treatment for nausea and vomiting during pregnancy is a combination of pyridoxine and doxylamine (Persaud et al., 2018). 
• An affordable and efficient over-the-counter treatment for preventing postoperative nausea and vomiting is dimenhydrinate. For this reason, Nabilone is likewise indicated (National Institute of Diabetes and Digestive and Kidney Diseases, 2017).

Anti-emetic Agents: 

• Ondansetron: It is a first-line drug for chemotherapy-induced, postoperative, and gastroenteritis-related nausea. It works as a selective 5-HT₃ receptor antagonist, blocking central and peripheral serotonin receptors (Griddine & Bush, 2023). 
• Metoclopramide: A prokinetic dopamine D₂ antagonist, enhances gastric emptying and reduces nausea in diabetic gastroparesis and migraines (Metoclopramide, 2025).  
• Promethazine: An antihistamine beneficial for general and vestibular-induced nausea; sedative side effects are frequent (Southard & Khalili, 2024).
• Domperidone: It is helpful for dyspepsia and gastroparesis and is a peripheral dopamine inhibitor, improving gastric motility (Reddymasu et al., 2007). Its use should be monitored by a healthcare provider due to potential cardiac risks.

Lifestyle Changes and Home Remedies: 

Managing mild to moderate nausea depends much on lifestyle and home remedies. Resting in an upright or semi-reclined position after meals helps reduce reflux and allows gravity to prevent stomach contents from rising, which can ease queasiness. Avoiding greasy, spicy, or highly seasoned meals is advised, as these might aggravate the stomach lining and exacerbate nausea; instead, eating plain, easily digestible foods such as toast, rice, bananas, or crackers may settle the stomach. 

Essential is staying hydrated; often, little sips of transparent fluids like water, diluted juices, or oral rehydration solutions help to maintain fluid balance without upsetting vomiting. Either as tea, capsules, or fresh slices, ginger has proven to be quite effective in alleviating chemotherapy-related nausea as well as pregnancy-related vomiting; peppermint oil (especially as aromatherapy) might soothe the stomach and help to lessen symptoms. 

Research has shown encouraging results with acupressure on the P6 (Neiguan) point, situated on the inner forearm, for minimising nausea, especially when applied consistently or via pressure bands. These non-pharmacological techniques together provide accessible and supportive methods to control nausea that, if necessary, can be securely utilised with medical treatments (Afshar et al., 2023). 

Daily tactics can make a genuine difference if nausea is chronic or repeated: 

• Keep a Symptom Log: Tracking information, including meals consumed, stress levels, and hobbies, helps to pinpoint individual triggers. Patients who journaled their symptoms had fewer nausea episodes and better communication with medical professionals, according to a chemotherapy study.
• Avoid Known Triggers: Strong scents, motion, and specific textures or tastes may make symptoms worse. Militating to make sure there is adequate ventilation and applying calming scents may help to lower cases of nausea.  journalled
• Medication Adherence: Using prescribed antiemetics (e.g., ondansetron or metoclopramide) as directed, ideally at the start of symptoms, to avoid escalation.
• Light Exercise: A brief stroll or stretches support digestion and may reduce nausea. Walking 15 minutes after a meal, according to one study, might help digestion and lessen stomach pain. 
• Patient Education: Patients who are feeling queasy should avoid spicy, greasy, or strongly scented foods and instead concentrate on eating small, frequent meals of bland, easily digestible foods. It's crucial to stay hydrated by taking tiny sips of clear liquids, particularly if vomiting is occurring. Symptoms can be lessened by avoiding abrupt movements and resting upright after meals. Patients should stay away from places with strong smells and tight clothing. They should get medical help right away if their nausea lasts longer than 24 to 48 hours and is accompanied by excruciating pain, dehydration, or blood in their vomit. 

• Suspect poisoning as the source of nausea.
• Watch for vomited material for blood or a coffee-ground-like substance.
• Experience strong headaches, blurry vision, mental disorientation, abdominal discomfort, or acute chest pain.
• Display indications of severe dehydration. Have a temperature over 101°F (38.3°C) with vomiting; suffer fast respiration or pulse; or have a rigid neck, sluggishness, or diminished awareness.
• Have been sick for more than twenty-four hours.
• For more than twelve hours, I have had trouble keeping liquids in.
• Vomited three or more times daily.
• Did not urinate for 8+ hours.
• Persistent, intense stomach pain.

When Should Children's Medical Attention Be Sought?

• Vomiting goes on for several hours.
• Diarrhoea, a fever over 100°F (37.8°C), or symptoms of dehydration accompany vomiting.
• No urine in six or more hours.

Patients should take home messages. Although nausea is rather frequent, it should not be disregarded, particularly when it is chronic or intense. It can indicate underlying medical issues needing immediate attention. Maintaining a balanced diet, controlling stress, and avoiding known triggers are crucial. Regular monitoring, appropriate hydration, and adherence to prescribed drugs assist in managing symptoms. Patients who experience chronic nausea may have to see either a neurologist or a gastroenterologist. Specific therapies like ginger or vitamin B6 might provide safe comfort for problems like pregnancy.