Understanding dehydration and its link to nausea
What is dehydration?
Dehydration is a condition in which the body lacks water and essential minerals such as sodium and potassium, which are necessary for proper bodily function. On average, water represents about 60% of an adult's body weight . This fluid plays a role in numerous physiological functions, including nutrient transport, waste elimination, and body temperature regulation . When water intake does not compensate for losses (through perspiration, urine, vomiting, and other factors that contribute to dehydration), an imbalance occurs, exposing the body to potentially serious health problems.
What can cause nausea?
Nausea originates from the activation of a specific area of the brain, often in response to digestive upset, infections, or the ingestion of irritants . When dehydration occurs, the resulting decrease in blood volume and altered electrolyte balance can disrupt the digestive system and the brain , thus contributing to the onset of nausea. Vomiting exacerbates the loss of water and minerals, creating a vicious cycle between dehydration and nausea. Nausea can also be caused by fatigue, digestive problems, mild illnesses such as gastroenteritis, or more serious conditions like meningitis.
Symptoms of dehydration and nausea
What are the first signs of dehydration?
The first signs of dehydration are usually thirst, dry lips, unusual fatigue , headaches , and nausea. Other, more serious symptoms may appear: dark and less abundant urine, dry skin , dizziness, confusion, or even behavioral changes. In cases of severe dehydration , blood pressure can drop, causing dizziness.
Specific symptoms according to age
Dehydration manifests itself differently depending on age. Children and the elderly are particularly at risk due to their physiological fragility.
In infants , water loss can be very rapid. Observable symptoms of dehydration include a sunken fontanelle (soft spot on the head), crying without tears, irritability, and rapid breathing. In very young children, this rapid water loss can lead to a weight loss of 10 to 15%.
In older adults , dehydration can manifest as dark urine, dizziness, loss of appetite, and unusual fatigue. These individuals are particularly at risk because their sense of thirst is often diminished, which reduces their ability to drink properly and can worsen dehydration. It is therefore essential to pay close attention to these vulnerable individuals and continue prevention efforts regarding the risks of dehydration in our senior citizens.
How can we differentiate between nausea related to dehydration and other causes?
To differentiate between nausea caused by dehydration and nausea from other causes, it's necessary to identify and analyze the symptoms associated with the nausea and the context in which it occurs. Nausea due to dehydration is often accompanied by specific signs such as intense thirst, a dry mouth, decreased urine volume (which becomes darker), unusual fatigue, dizziness, or fever. It frequently occurs after excessive sweating, vomiting, diarrhea , or insufficient fluid intake. Conversely, if nausea is accompanied by fever, severe abdominal pain, acute diarrhea, during other medical treatments, or in the context of infections, another cause is likely.
The main causes of dehydration
Dehydration results from an imbalance between fluid intake and loss . Insufficient water consumption is often the cause of a fluid deficit , but other factors can also lead to dehydration. Excessive sweating, caused for example by high temperatures or intense physical activity, vomiting, or diarrhea cause the body to lose water and minerals, resulting in a lack of hydration. Certain chronic diseases (diabetes, kidney failure), age, fever, prolonged sun exposure, or alcohol consumption increase water and mineral loss and therefore worsen cases of dehydration.
Solutions for dealing with dehydration and nausea
How to rehydrate quickly?
To compensate for dehydration, it is essential to drink both water and replenish electrolytes (sodium, potassium, magnesium, etc.) in the body. Oral rehydration solutions (ORS), available in pharmacies, are particularly effective because they contain the correct balance of water, glucose, and electrolytes needed by the body. Drinking water remains a basic option, but in cases of significant fluid loss (gastroenteritis, vomiting, diarrhea), it is recommended to use ORS . In case of dehydration, it is important to avoid alcoholic or caffeinated beverages, which increase urine output and therefore prevent proper hydration. In general, alcoholic beverages should be consumed in moderation. Excessive alcohol consumption is dangerous to your health.
What should I drink if I feel nauseous?
In case of nausea, certain foods can help relieve symptoms. Ginger and mint are known for their soothing properties and aid digestion. They can be consumed as infusions or herbal teas. Maintaining good hydration is also essential. Drinking water and other soft drinks frequently, in small amounts , helps prevent dehydration. Clear broths, such as vegetable broth, are recommended because they provide essential minerals while being easy to digest.
How to stay hydrated when you feel nauseous?
If you feel nauseous, it's recommended to drink small sips regularly, rather than large amounts, to avoid overloading your stomach. You can also eat water-rich foods like watermelon, cucumber, oranges, or soups to help your body rehydrate properly.
When should you consult a doctor?
A doctor should be consulted promptly if dehydration worsens . Warning signs include confusion, loss of consciousness, persistent vomiting that prevents hydration, high fever, or, in infants, a sunken fontanelle or crying without tears. The elderly and those with chronic illnesses should also be closely monitored. A doctor may then recommend various treatments to help the body rehydrate.
Preventing dehydration and nausea
To prevent dehydration and nausea, it is advisable to adopt a hydration routine adapted to your daily needs. Drink the recommended daily water intake regularly ( A minimum of 1.5 to 2 liters of water per 100 liters is necessary for an adult, and this should be adjusted according to age, physical activity, and weather conditions. Hydration products containing electrolytes, essential minerals for proper bodily function, can be incorporated into your routine to optimize fluid balance during exertion or in intense heat. To supplement fluid intake, foods rich in water (fruits, vegetables, soups) can be considered.
Bibliography
Duggan, C., Refat, M., Hashem, M., Wolff, M., Fayad, I., & Santosham, M. (1996). How valid are clinical signs of dehydration in infants?. Journal of pediatric gastroenterology and nutrition , 22 (1), 56–61. https://doi.org/10.1097/00005176-199601000-00009
