Water's Journey Through The Body

You've taken a sip of water - what happens next? Where does it go?

By: Aditi Pai

Water is the Swiss Army Knife of the body. Take a multi-tool along on a road trip and you’ll end up the resident handy-person of the trip. Similarly, take a drink from a bottle of water and kick off a long journey for said water to travel through the body during which time it will accomplish a number of important tasks.

So how long does it take for water to reach the bladder? The average person can process about 33.8 ounces of fluid per hour, but only 20% of the water you drink actually makes it to the bladder. Along the way, water will stop to perform many other necessary errands, making it crucial to drink healthier, filtered water that’s free of harmful toxins and contaminants.

Water will act as a lubricant to organs, remove waste, regulate body temperature, and aid the body in nutrient absorption.

The best way to learn about the myriad of roles water plays in the body’s daily functions is to discover where it goes when you drink it by tracking its journey from beginning to end.

Where does water go when you drink it?

Water’s journey first begins in the mouth. The first big step in the process is the body registering hydration. After a few gulps of water, the brain will convince the body — prematurely – that the body has had enough to drink.

This is an important hydration mechanism because it takes a long time for the water that was drunk to reach cells and provide them with sufficient hydration. If the brain registered hydration only after cells received water, people would be drinking way more than the body really needs. The communication between the brain and mouth allows someone to stop drinking at the appropriate time, even if the water hasn’t fully hydrated the system yet.

From there, water travels through the esophagus, which is a small pipe connected to the mouth, and lands in the stomach. A lot of people wonder “how long does it take for water to digest?”, but one of the main differences between eating food and drinking water is that water is absorbed rather than digested. In the stomach, the process of water absorption to the bloodstream begins.

The amount of water absorbed in the stomach and how quickly water is absorbed depends, in part, on how much has been eaten. If someone is drinking water on an empty stomach, they are more likely to experience a faster rate of water absorption – as quick as 5 minutes after taking a drink. Whereas, if a person has eaten a lot of food before they drink water, the speed of absorption will slow down accordingly and absorption could take up to a few hours.

what functions does water serve in the body?

A majority of water’s absorption into the bloodstream occurs after water passes through the stomach and into the small intestine. The small intestine, at around 20 feet long, is the organ primarily responsible for water absorption through its walls and into the bloodstream. From here, water will travel to cells across the body, providing them with the hydration to perform daily functions efficiently.

One such task is filtering toxins. This is primarily the job of the kidneys, but to filter toxins efficiently, kidneys require a large amount of water. If the kidney does not receive enough water, it could lead to health concerns including kidney stones and other kidney-related diseases. Fortunately, one way the kidneys inform someone of whether they’re providing their body with enough water is by concentrating the amount of water expelled through urine – thus changing the color of urine to bright yellow.

Another vital function of water is keeping brain cells hydrated to maintain cerebral functions. Without the appropriate level of hydration, studies have shown that people experience impaired short-term memory function and visual motor skills.

how is water removed from the body?

Once the human body uses up all the water it needs to function efficiently, it begins the process of removing excess water.

Water leaves the body in four main ways: through the kidneys, skin, large intestine, and mouth.

The most high-profile exit strategy of water is through the kidneys via urine. Kidneys use water to filter toxins out of the body, but when the kidney has used as much as it needs; it gets rid of the rest through urine. This method of releasing water is incredibly useful to learn about levels of hydration, which can be discerned from the color of the urine.

This also ties back to the question “how long does it take water to reach the bladder?”, as your hydration level determines how quickly your body will send water to your kidneys which then goes to the bladder once it gets processed as urine. If you’re very hydrated, your body will send the excess water into the kidneys quickly because it’s not needed elsewhere. If you’re dehydrated, the water will be absorbed and sent to maintain vital functions before it eventually reaches the kidneys to remove toxins.

Another exit point for water is through stools. Healthy fecal matter consists of 75% water and 25% solid matter. Once the small intestine has absorbed enough water to send throughout the body, it will pass the water along to the large intestine. When water reaches the large intestine, it will combine with solid matter to soften stool and aid digestion.

When someone exercises or heats up, small droplets of water, also known as sweat, will appear on the skin to cool the body. Sweat is a natural way the body regulates its temperature. It’s estimated that most individuals sweat at a rate of 500 to 700 mL per day, but people can sweat at a rate of up to one liter per hour during high-intensity exercise in a hot environment. While drinking water during exercise will help replace these fluids, the best strategy is to continuously drink water throughout the day to ensure adequate hydration.

Small droplets of water also exit the body via the breath. This is most evident on a cold day when a person can clearly see their breath. Nonetheless, it occurs with every breath we take and is one of the main reasons someone may feel slightly dehydrated in the morning after a full night of restful sleep.

Now that you know what happens to water in your body, learn about different types of water and find out how much water you should consume daily.