We all know that water is key to survival. But have you ever wondered what happens to water when you drink it?
Water doesn’t just pass through our bodies without touching the sides. Much of the water we drink is used for vital bodily processes and spreads beyond the stomach and the digestive system.
In this guide, we’ll be sharing water’s journey through the body, and why drinking water is so essential for health.
Table of Contents
🤔Why Water is So Important for the Human Body
Water is important for the human body because it is used for so many necessary purposes as it travels towards the bladder.
On its journey through your body, water is used to remove waste, lubricate organs, regulate body temperature, and support the absorption of nutrients. In fact, around 70% of water doesn’t even make it to the bladder, because it has more important functions elsewhere in the body – and up to 60% of the adult human body is made up of water.
In short, we couldn’t live without water. Drinking water is essential to human health, affecting a whole host of bodily functions. The more water – and the higher-quality water – we drink, the better our bodies will be able to keep in order.
Can any type of water be used by the human body?
Yes – if you were in an emergency situation with no other option, drinking dirty water would be better than drinking nothing.
However, clean water should be prioritized because it doesn’t carry the risk of pollutants or contaminants that could have serious health effects. That’s why so many people choose to filter their water nowadays: because filtered water is free from contaminants, making it much healthier and safer to drink.
Learn more about the different types of water in this post.
💪What Does Water Do For the Body?
We know that water is essential, but what makes it so necessary for humans? Let’s take a look at some of the functions that water has in the body.
Water and the Brain
One of water’s most important functions takes place in the brain. Water hydrates brain cells and allows them to perform cerebral functions – which control movement and regulate body temperature.
The brain plays a key role in telling the body what to do – including what to do with water. When the brain cells are suitably hydrated, the brain can perform at its best.
Water also provides nutrients to the brain, which support brain health by helping us to maintain focus, decreasing mental fatigue, and improving concentration.
Water and the Kidneys
Water is vital for the kidneys – and, in fact, the kidneys could not function without water. The primary job of the kidneys is to filter toxins out of the body.
At peak health, kidneys can filter around half a cup of water per minute. Aside from removing waste from the body, kidneys are also essential for making hormones that are used to make red blood cells, maintain strong, healthy bones, and control blood pressure.
Water helps kidneys to filter waste, and keeps the blood vessels dilated, which allows blood to travel freely to and from the kidneys.
Drinking too little fluids can cause serious kidney issues, including kidney stones and a kidney infection.
Water and Body Temperature Regulation
Water can transfer and absorb heat effectively, which is why it is used to control body temperature.
Because of water’s high heat capacity, it can absorb a lot of heat before it increases in temperature. Water is used to hydrate every cell, which prevents sudden temperature changes in the body.
Blood is made predominantly of water. To conserve heat, blood transports heat to vital organs from the extremities, and to release excess heat, it flows towards the surface of the skin. Water also releases excess heat when we breathe and sweat, through water vapor in our breath and skin.
Water and Digestion
Increasing fluid intake is often recommended to people with constipation, and this is because water – or a lack of it – is a big risk factor for constipation.
Water has a double action in the small intestine: water absorption allows the human body to absorb nutrients, and water molecules are also required to soften stool.
Increasing hydration is the best way to prevent constipation. One study found that intake of mineral water containing sodium and magnesium is best for improving the frequency and consistency of bowel movement.
Water and Weight Loss
Drinking water can increase satiety – the feeling of fullness – which can help people to lose weight. Water can also boost the metabolism, speeding up the rate at which you burn calories from food throughout the day. Again, this can be helpful for people trying to get rid of excess body weight.
Excess water in the body can increase body weight – but this is known as water weight, and it’s usually only temporary. Water intake before meals can prevent you from eating as much food because the fluid in your body makes you feel full.
One study found that when overweight people drank 0.5 liters of water three times per day before meals, this water intake helped them to reduce body weight and body fat.
Water and Headache Prevention
Water doesn’t only facilitate processes in the body; water can also reduce headaches and migraines in some people, according to science.
Dehydration – when your fluid intake is too low – is often associated with headaches. So, drinking water can prevent headaches simply because your body is getting the volume of water it needs.
Some studies show that hydration can relieve symptoms in people who experience frequent headaches. For instance, this study found that when people with migraines increased their fluid intake, their improved hydration reduced the severity of their migraines.
🔄How Does Water Travel Through the Body?
If you’re keen to learn about water’s journey throughout the body, the step-by-step journey is outlined below:
Step 1: Water Travels Through The Mouth
The first stage of water’s journey is when it is swallowed. Most of us subconsciously drink fluids until we feel like we’ve had enough. This feeling is brought on by the brain, which tells us that we’re suitably hydrated.
Interestingly, this is a premature feeling.
We’re not actually hydrated the instant that we drink water, because it takes a while for the water to reach our bodies’ cells. However, if the brain waited until we were actually hydrated before telling us we’d had enough, we’d end up drinking far too much water in one go.
Step 2: Water Travels To The Stomach
After being swallowed and traveling down the esophagus, water arrives in the stomach. Unlike food, water isn’t digested – it’s absorbed. This absorption process begins in the stomach.
The amount of water that is absorbed depends on how much you’ve consumed, and the rate at which water is absorbed depends on how much you’ve eaten.
If you’ve just eaten a heavy meal, water will be absorbed at a slow rate, and it might take a couple of hours before the body’s cells are hydrated. If you’re drinking water on an empty stomach, water will be absorbed much more quickly, because the stomach isn’t full of food. Water can be processed within 5 minutes on an empty stomach.
Step 3: Water Passes Through The Small Intestine
The small intestine isn’t actually very small – it’s about 20 feet long. The small intestine absorbs water into the bloodstream, through the cell membrane. Once absorbed, water can travel in the blood to cells throughout the body, ensuring that the body is suitably hydrated.
By this point, most fluids have been absorbed by the body. But the process doesn’t stop there – it continues in the large intestine.
Step 4: Water is Reabsorbed by The Large Intestine
The large intestine reabsorbs water, which is used to concentrate fecal matter. The large intestine also absorbs the remaining water from any materials that haven’t been digested in the stomach as food.
As well as absorbing fluids, this intestine absorbs minerals and electrolytes, and is cleverly designed to prevent the backflow of electrolytes into the blood. The intestine then propels fecal matter towards the rectum for elimination.
Step 5: Water Enters the Kidneys
As we know, water is essential for the kidneys. The kidneys rely on water to filter toxins out of the body. When the kidneys eliminate toxins through urine, water is eliminated from the body, too.
The kidneys have a clever way of telling us whether we’re drinking enough fluids: through the color of our urine. Bright yellow urine is a sign that the body isn’t getting enough hydration, while pale yellow or clear urine is a sign of good hydration.
Step 6: Water Leaves the Body
Finally, any water that isn’t required in the body can be removed. The below section of the guide discusses several of the ways that excess water can be removed from the body.
🚽How is Excess Water Removed from the Body?
Excess water that isn’t needed for processes throughout the body can be removed. There are several ways that the human body removes water, including:
Through the Urinary System
The urinary system acts as a filter for blood. It ensures that waste, toxins, and excess salts are removed from the body through urine – and excess water makes up a good portion of urine.
There are different stages of filtration in the urinary system, including filtering blood, separating healthy, necessary nutrients from toxins, storing urine, and expelling urine from the body.
Here’s an overview of the stages involved in the urinary system:
- The kidneys receive blood through a number of tiny arteries
- The kidneys filter this blood, separating the toxins from the healthy nutrients
- Proteins, vitamins and minerals are sent back into the bloodstream
- Waste products are combined with water and sent to the bladder as urine
- When you go to the toilet, urine travels through your urethra and leaves your body
Drinking lots of water can help with stool softening, ensuring that stools are easy to pass.
That doesn’t mean that the more water you drink, the softer your stool will be – there’s a limit to how much excess water is eliminated in stools (unless you have diarrhea, which is an unpleasant sign that your body isn’t functioning properly).
In most cases, water is diverted into stools through the colon. Muscle contractions push the stools towards the rectum, where they are expelled.
Sweat, or perspiration, is the act of releasing water through the skin as an act of cooling, when the body’s internal temperature rises. Sweating usually occurs when we’re hot or when we’re working out.
Sweat glands are found in the majority of mammals. When our body temperature rises, our sweat glands are stimulated to secrete water to the surface of the skin by the sympathetic nervous system. We use sweat as a means of temperature control.
We all sweat a small amount of water on a daily basis, especially in areas such as the feet and under the arms.
However, our bodies sweat as a response to overheating, not as a response to how much water we’ve consumed. This means that, although sweat can be used as a means of eliminating excess water, it isn’t dictated by how much water we drink. So, drinking lots of water won’t mean that you sweat excessively.
Through the Breath
If you hold your hand in front of your mouth and breathe onto it for several seconds, you’ll notice that your hand isn’t only hot – it’s also damp. That’s because a small amount of water is released through our breath.
Our bodies lose water consistently as we breathe. Unlike sweating, which we may do more on some occasions (such as during a workout) than others, we breathe every hour of every day, which means we lose the same amount of water regardless of what we’re drinking.
We lose about a cup of water every day just through breathing.
Why do we lose water when we breathe? The air in our lungs is humidified (increasing its moisture content). When we exhale this air out of our bodies, it has a naturally high water content. Exhaled air is completely saturated with water, and has 100% humidity.
💬Drinking Water FAQs
How many liters of water should we drink per day?
Science says that women should drink 2 liters of water per day, and men drink 2.5 liters per day. However, all bodies are different, with their own functions and requirements.
The healthy amount of fluids might be different for one person than it is for another – for instance, athletes who exercise and sweat a lot will need to replenish their fluids faster than people who live a sedentary lifestyle, who would require less water.
Listen to your body’s needs. Make sure you’re drinking 2 liters minimum, and drink more if and when you’re thirsty.
What type of water is best for the body?
Tap water is fine for hydration, but there are certain fluids that are better for the body than others.
Mineral water, containing sodium, magnesium and calcium, has obvious benefits, providing minerals that the body needs to function properly. Absorption of minerals through fluids has a number of benefits, helping with the regulation mood, digestion and blood sugar, and improving immunity, bone strength, and sleep quality, when they’re carried around the body in the bloodstream.
Filtered water is also better for your body because it doesn’t contain traces of contaminants (found in most municipal water supplies) that could be harmful if digested by the body. Absorption of some contaminants, even in a low volume, can have health repercussions, and filtered fluids are safe because they’re free from these impurities.