Water intake is a popular drink only to have when you are thirsty and to maintain hydration. But did you know that water intake can also be responsible to make you more alert? Studies have shown that water can do much more than just quench your thirst. Water can stimulate the fight and flight response of the nervous system, which can raise alertness and make you active.1 So, does water raise blood pressure?
Ideally, water is required by all your body cells to perform their function. Adequate water intake may differ from person to person, based on your need but staying hydrated is important. While the right amount of water intake is not known, the general understanding of having eight glasses a day can be a good measure, to begin with. This is particularly important for people involved in strenuous physical activities, and sports, those who are more prone to dryness, dehydration and experiencing conditions like recovery from illness, pregnancy, or lactation. However, there can be a problem when excess water is taken.
Does Water Raise Blood Pressure?
Contrary to the belief that water does not affect blood pressure, scientists have now discovered that water can have an impact on your blood pressure. The intake of water is linked to sodium in your cells, which is responsible for several important functions including maintaining a balance of fluids. The impact of water on blood pressure and whether water can raise blood pressure or not can be a piece of crucial information in managing low and high blood pressure.
A 2007 study showed the effect of acute water consumption on hemodynamics and autonomic responses of hypertensive and normotensive individuals. It was noted that the systolic and diastolic blood pressure increased in both groups after consumption of water. It was concluded that water intake results in a pressor response that increases vasoconstrictor sympathetic activity, causing an increase in blood pressure.2
A trial conducted in 2010 studied the effect of increased intake of water on ambulatory blood pressure in healthy subjects. It was observed that an intake of two liters of extra water intake significantly raised the daytime blood pressure in these healthy subjects and also reduced a sense of vertigo.3
In yet another study it was reported that drinking water raised sympathetic activity, which raises norepinephrine levels. These further increases blood pressure in autonomic failure patients, which can be useful in planning management to improve symptoms in patients with orthostatic hypotension or low blood pressure caused due to postural changes.4
Experts at Vanderbilt University Medical Center found that water intake increases the fight or flight response of your nervous system which can raise alertness, blood pressure, and energy expenditure.1 It began with observing the curious nature of water to increase blood pressure in patients who could not maintain their blood pressure within normal levels. It was noted that although there was not much difference in healthy individuals, water intake helped in increasing sympathetic activity and constricting blood vessels that could prevent the pooling of blood in the lower limbs. Thus, this was more useful in people who needed better management to maintain their blood pressure within a normal range.
This finding was also thought to be useful in the case of blood donors, where some may experience passing out after blood donation. As water can raise blood pressure, this ability can help in preventing or managing fainting in such people and reduce the unpleasant feelings that can get associated with blood donation.1
These reviews fairly answer the question – does water raise blood pressure? These findings can be used to the best of our abilities to manage individuals who cannot maintain blood pressure or during such conditions when we need to increase blood pressure.
Can Excess Water Raise Blood Pressure?
As drinking water can raise blood pressure, it can be good for those who have low blood pressure and it can prevent fainting too. But what about those who have high blood pressure?
When you drink too much water it can cause water intoxication or even disrupt the functioning of the brain. Excess water can cause the body and brain cells to swell. Overhydration can also cause reduced levels of sodium, called hyponatremia, which results in fluids entering the cells, resulting in swelling. It can symptoms like drowsiness, headache, confusion, high blood pressure, and low heart rate. This increases the risk of seizures and coma. This can also be more of a concern for people with high blood pressure, heart disorders, and other chronic illnesses.
Usually, you drink water when you are thirsty, when you sweat a lot or when you have done physical activities. Drinking water when not needed can result in an excess intake of water. You may be able to keep a watch on certain things to monitor if you drinking too much water. Normally, the color of urine is pale yellow. However, if you note your urine is often clear, it may be because you are drinking too much water during that period.
Other signs of headache, nausea, muscle cramping and fatigue can be due to water and electrolyte imbalance or even related to high blood pressure. It is best to seek medical advice if you experience any of these.
Conclusion
Studies have shown that water can raise blood pressure. This can be used to clinical advantage by planning a routine with adequate water intake for those with low blood pressure, postural hypotension, or those who tend to faint due to a drop in blood pressure. Monitoring or increasing water intake can also be helpful for those experiencing situations that can cause a drop in blood pressure like blood donation, or women may experience during menstruation, pregnancy, or lactation. However, as water can raise blood pressure, individuals having high blood pressure, or heart or kidney disorders need to be more conscious and follow medical advice, as needed.
