Water is essential for maintaining the body's basic metabolic and circulatory functions. About 60-70% of the human body composition is water. Blood vessels, in particular, are 90% water. Therefore, any variations in the body's water content can substantially impact the dynamics of blood flow or hemodynamics and have a direct impact on blood pressure. We spoke to our expert Dr Rockey Katheria, Consultant–Interventional Cardiology, Manipal Hospital, Varthur Road, Bengaluru, who explained the impact of dehydration on our blood pressure numbers and how to stay hydrated.
Causes Of Dehydration
“Dehydration occurs when the body loses more fluid than it absorbs. This can happen for both physiological and pathological reasons. Dehydration can occur physiologically as a result of physical activity or excessive sweating brought on by the heat. Pathologically, conditions like infections that cause persistent vomiting or diarrhoea cause dehydration,” said Dr Katheria.
Also Read: Stay Hydrated and Refreshed: Healthy Electrolyte-Rich Drinks to Prevent Dehydration
Effects on Blood Pressure
In most cases, dehydration leads to low blood pressure (hypotension). However, in some cases, it may also cause high blood pressure (hypertension).
Hypotension
“Dehydration is characterised by a significant drop in blood volume and insufficient fluid in the arteries. Because of this, the arteries are unable to produce enough blood pressure, which leads to hypotension and its associated symptoms,” said Dr Katheria. This includes lethargy, fatigue, exhaustion, dizziness, and loss of mental alertness. In severe situations, syncope (fainting) may result.
Hypertension
“Alternatively, in some cases, brain-regulated mechanisms within the body may get triggered to counteract dehydration by vasopressin release. Vasopressin, a hormone released by the brain, works to conserve water in the kidneys, which can result in increased blood pressure,” added Dr Katheria.
This response, however, might not be sufficient to counteract severe dehydration, and in some cases, it might even contribute to high blood pressure. Furthermore, dehydration not only affects blood pressure but can also impact vital organs like the heart, brain, and kidneys, potentially leading to acute renal failure.
A 2022 study revealed a strong link between hydration levels and hypertension status. People with hypertension were found to have elevated levels of Extracellular Water (ECW), which could be attributed to higher salt intake or compensatory mechanisms for chronic dehydration.
Maintaining Adequate Fluid Balance
It is crucial to maintain an adequate fluid balance in the body, especially during hot and sunny days when the risk of dehydration increases due to higher temperatures and increased sweating. “To maintain the right fluid balance, it is recommended that adult men consume around 3.5 litres of water per day, while adult women should aim for about 2.5 litres per day. However, the required water quantity can vary based on factors like activity level, climate, and individual health conditions,” highlighted Dr Katheria.
Tips for Staying Hydrated
Here are some effective measures to prevent dehydration, as listed by Dr Katheria:
- Don't forget to stay hydrated by drinking water regularly throughout the day.
- Limit the consumption of dehydrating beverages, such as coffee, tea, and alcohol.
- Ensure enough water intake before starting any physical activity.
- Hydrate during exercise and replenish the fluids afterwards.
It is also essential to be aware of signs of dehydration and take appropriate measures to reverse it. If symptoms are severe, seeking medical help is also important.
Message From The Expert
Dr Katheria concluded, “Dehydration can significantly affect blood pressure and cause either hypotension or hypertension. Maintaining proper hydration can prevent these adverse impacts. It is important to take precautions to stay adequately hydrated. By making conscious choices to drink enough water and limit dehydrating beverages, you can help ensure your body functions optimally in every season.”
[Disclaimer: This article contains information provided by an expert and is for informational purposes only. Hence, we advise you to consult your own professional if you are dealing with any health issues to get the necessary treatment.]