Those of us with hypertension will do well heed the warning given by the aged seafarer to the wedding guest in Samuel Taylor Coleridge's poem. We may no longer recall any of the Rime of the ancient Mariner other than “Water, water everywhere, Nor any drop to drink.” The old sea dog is talking about dehydration. And dehydration can cause high blood pressure in at least two ways.

How much water do we need?

It is a common misunderstanding that we need to drink two liters of water a day to keep our bodies properly hydrated. It is true that we do need at least that amount of water each day, but provided we have a suitable diet, much of it will come from our food.

Dehydration and hypertension

We become dehydrated when we lose water from our bodies, for example by perspiration when we are hot or even from the effect of air conditioning, and do not replace it with sufficient quantities of fluids.

There is much more to dehydration than having a parched throat and feeling thirsty. When dehydrated, we lose about 6% of the water content from the cells within our body. The result is that the smooth muscles surrounding our arteries and blood vessels become less supple and are unable to expand properly to accommodate our systolic pressure.

This causes hypertension because the pressure within our arteries and blood vessels has to increase to maintain blood flow.


We need a certain amount of sodium in our diet. Sodium is an important electrolyte that operates outside of our cells for the proper functioning of our nerves and muscles. It also influences blood pressure and blood volume. When we are properly hydrated, our bodies are better able to regulate the effects of sodium by flushing out any excess. However, as we lose water content when we are dehydrated, we are less able to eliminate excess sodium and that causes hypertension.

Reduce hypertension by proper hydration

Unknowingly, like the ancient mariner and his shipmates in Coleridge's poem, we may be suffering from the effects of dehydration. The old salt's ship was becalmed for many days as idle as a painted ship upon a painted ocean and they ran out of drinking water. We, on the other hand, have access to sufficient water to drink, but we may not be keeping ourselves properly hydrated because of our poor diet and high sodium consumption. And that might be the cause of or a contributing factor in our condition.

An excellent way of helping to keep ourselves properly hydrated and thereby lowering our high blood pressure is to follow a healthy, balanced diet that is rich in fresh fruits and vegetables, and contains whole grains and lean protein, but is low in sodium. We also need to drink sufficient cold water each day to compliment our healthy eating plan and reduce our hypertension.