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11 Consequences of Not Drinking Enough Water

Not drinking enough water

It is hard to estimate how many times you’ve heard sentences like “More than 60 % of the human body is made up of water and water is needed in every cell of the body” throughout your life.

We all know the significance of water for the human body. However, despite this awareness, the number of people who consume 7-8 glasses of water or more in a day appears to be less than those who don’t.

Being unaware of the health problems that can occur due to insufficient water consumption may become an explanation for why most of us do not pay attention to the amount of water we consume in a day.

Realising these potential health consequences of inadequate water consumption may urge you to be more careful about how much water you drink in a day.

By all means, your body can tolerate a couple of days or weeks without drinking a sufficient amount of water. However, when insufficient water consumption becomes a habit, it can pose serious health conditions, especially in the long run.

In this article, we will look at 11 potential health consequences of not drinking enough water.


Note: Experts indicate: that if you have heart failure, you may need to limit your daily water intake. Because people with heart failure may not be able to tolerate 2 litres or more water daily. Therefore, we strictly recommend you talk to your doctor about your daily water requirement if you have this medical condition. Your doctor/physician will determine the right amount of water for you (1).

Now, let’s focus on 11 consequences of not drinking enough water.


1- Low Energy

So to speak, you are punishing your internal organs, but mainly your heart, by depriving them of water. Because, in the case of insufficient water intake, your heart will have to work harder to deliver oxygen and nutrients to your brain, muscles and skin. That extra effort of your heart, in turn, will consume your energy resulting in tiredness (2). 

If you complain about chronic tiredness, there can be various reasons behind this. However, if you aren’t drinking at least 6 glasses of water daily, then dehydration can be the underlying reason for your inexplicable exhaustion.

Endevaour to increase your fluid intake during the day and monitor yourself whether you feel more energetic and robust as a result. If you feel energetic after you have increased your daily water consumption, then presumably dehydration was the underlying reason for your constant fatigue.


2- Weakened Immune System

Water enters your body through your mouth and leaves your body through kidneys ( urine), skin ( sweat ), large intestine ( stool), and mouth (droplet) (3). 

While leaving the body, water takes toxins, bacteria, viruses and waste materials along with it.

When you do not drink enough water, your urine output decreases consequently. And, this makes you more susceptible to illnesses due to the fact that waste materials and toxins dwell longer in your body.

In a nutshell, constant dehydration increases the burden on the immune system which in turn makes you susceptible to illnesses. 


3- Poor Skin

Skin health is arguably one of the most incentivising factors for so many people to drink more water. Particularly ladies – who are aware of the fact that insufficient water intake brings about many skin problems from premature wrinkles to skin sagging – tend to drink a sufficient amount of water. 

In addition to skin sagging and premature wrinkles, insufficient fluid intake decreases the amount of water retained in the skin, thus causing the skin to appear dull, tired and dry.

What’s more, inadequate daily water consumption can be the culprit for blackheads and acne flare-ups.


4- Weight Gain

For many experts; inadequate water consumption paves the way for weight gain.

Firstly, they explain this claim by the fact that many people mistake hunger for thirst. To be more precise, nearly 40 per cent of people mistake hunger for thirst, according to a report (4).

The second reason why insufficient water intake is linked to weight gain stems from water’s appetite-suppressing effect. That indicates if you always drink less water than you need, you might be prone to eat more during the day. 


5- Kidney Stones

Kidneys work as a filter that flushes out the build-up of waste and toxins in the form of urine.

If your daily fluid intake is insufficient it may result in metabolic waste products being retained in the kidneys and contribute to the formation of (painful) kidney stones.

Above all, according to the National Kidney Foundation; long-term inadequate water consumption may lead to permanent kidney damage (5).


6- Constipation

If you tend to get constipated frequently, you may want to ponder whether you are consuming enough fluid during the day. Because, as indicated in the research, dehydration is one of the main causes of constipation along with reduced physical activity and insufficient dietary fibre intake (6).

Water is essential for a healthy bowel movement. It keeps stool soft, thus enabling it to pass through the digestive tract with ease.


7- Muscle Cramps

In everyday life, it is less likely that you would experience muscle cramps due to dehydration. However, if you do exercise when your body lacks water, you can experience dehydration-related muscle cramps during or after exercise. 

According to Orthoinfo: even mild dehydration can hurt athletic performance as the body doesn’t have enough fluid to sweat during the exercise (7).


8- Unstable Blood Pressure

High and low blood pressure are two conditions that can affect the human body in different ways. High blood pressure is more serious relative to low blood pressure. Nevertheless, low blood pressure as well can pose serious health conditions. Therefore, it is important that blood pressure levels should be neither low nor high. 

Dehydration is known to cause low blood pressure. According to Healthline; if blood pressure level is too low organs and tissues don’t receive enough nutrients and oxygen that in turn brings about serious complications (8).

However, studies carried out in recent years, suggest that years-long insufficient water intake can lead people to hypertension. According to a report published by Medical West Hospital; high blood pressure is common in people who are chronically dehydrated (9).

To sum up; not drinking enough water can cause low blood pressure in the short term whereas causing high blood pressure in the long term.


9- Headaches

If you suffer from frequent headaches ask yourself whether you drink enough water during the day. Because, if your daily fluid intake is usually insufficient, this might be the culprit for your constant headaches. Nonetheless, it is important to note that there can be various reasons for headaches.

How dehydration sets the stage for headaches is explained by the physical changes of the brain when it lacks water. According to experts; when water intake is insufficient, it shrinks and pulls away from the skull, resulting in a headache (10).


10- Bad Breath 

If you are suffering from bad breath, despite all your efforts practising good oral hygiene, it may be due to inadequate water intake. But, whatever the underlying cause, your dentist is the one who will determine the exact reason for bad breath.

Water is necessary for the production of saliva.  A low water intake impacts the ability of the salivary glands to produce saliva which is critical to the digestion of food and also helps to regulate the bacterial numbers in the oral cavity.

So, if water intake is insufficient, bacteria can build up in the mouth and set the stage for bad breath, especially in the long term.


11- Impaired Cognitive Functions

As we discussed earlier, not drinking enough water can impact the brain causing headaches. In addition to headaches; difficulty remembering things, concentration problems and brain fog are also among the short-term effects of not drinking enough water.

While these are short-term effects of inadequate water consumption, long-term effects can be more serious. According to experts; years of insufficient water consumption can bring about cognitive disorders such as dementia and Alzheimer’s.


What Should be the Daily Water Consumption?

We have all heard from experts that 8 glasses of water per day is ideal for most people. The reason they say for most instead of for everyone is because how much water a person needs shows alteration based on many factors such as climate, season, height, weight, medical condition, and sex to name but a few.

For instance; if you have an intense workout routine or if you live in a humid climate you may need to exceed the ” recommended” 8 glasses of water a day.

Therefore, an expert can’t determine how much water you need without considering certain things about you and your life. However, if you haven’t talked to an expert as to the right amount of water consumption for you, the followingS can help you determine how much water you may need to drink a day.


Adult Men

The U.S. National Academies of Sciences, Engineering, and Medicine suggest that; a healthy adult man should consume 15.5 cups equals 3.7 litres of fluid. However, that includes the fluid that comes from food and other beverages.

As for only water; According to Mayo Clinic; 8 glasses of water daily is sufficient enough for a man to stay hydrated (11)


Adult Women

Once again; according to The U.S. National Academies of Sciences, Engineering, and Medicine; a healthy adult woman needs 11.5 cups equals 2.7 litres every day. 

6-7 glasses of water every day would be sufficient for most women. 


Pregnant Women

The general opinion is that pregnant women should drink between 8-10 glasses of water every day. However, since pregnancy is a delicate process, it is best to talk to a physician about the right amount of water intake during pregnancy. 


Breastfeeding Women

While an adult healthy woman needs 6-7 glasses of water per day to quench her thirst, this figure goes up to about 12 glasses for breastfeeding mothers (12).



According to the European Food Safety Authority; 6-8 fluids would be sufficient for children between 3-14 to stay hydrated (13).


Note: As we mentioned at the beginning of the article, people with heart failure shouldn’t aim to increase their daily water intake, because, it may bring about problems. In addition to heart failure; people with kidney failure as well shouldn’t aim to drink too much water. Therefore, we strictly recommend people with these medical conditions consult with their doctors about the right amount of daily water intake. 

Tarkan is an experienced health writer ( currently more than 600 articles ) and also the founder of this website namely His expertise in health stems from in-depth medical research and knowledge which he obtained over the course of many years.

Tarkan enjoys sharing factual knowledge on health, psychology and nutrition. He always aims to deliver evidence-based recommendations, provide links to related scientific studies.

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