Why Do I Feel Nauseous After Drinking Water?

Whenever you’re thirsty, your first instinct is most likely to reach for a glass of water. Water is an excellent thirst quencher, as it’s free from all those calories and additives that often pull water from the body. But do you ever notice that your stomach sometimes feels a bit wonky after a few gulps, like you’re about to throw up?

Let’s discuss several possible reasons for this and how to prevent it. That way, you can hydrate without worrying about feeling queasy afterward.

Quick Disclaimer: This article is solely for educational purposes and is not intended as personalized medical advice. If you have concerns about or are experiencing nausea or other digestive problems after drinking water, please consult a licensed medical professional.

What is nausea and how do you know you’re nauseous from water?

Nausea is a feeling of being sick to your stomach. It’s that uncomfortable sensation in the back of your throat or inside your stomach that makes you feel like you might vomit. You may also experience weakness, sweating, and a buildup of saliva in your mouth.

Feeling nauseous is your body telling you something’s “off” in your digestive system. It usually occurs from stomach viruses, morning sickness in pregnancy, motion sickness, food poisoning, etc. However, drinking water may also be a sneaky culprit.

Possible Reasons You Feel Nauseous After Drinking Water

If you often have an upset stomach after gulping down a tall glass of water, it could be due to any of the following reasons:

You have acid reflux.

When stomach acid flows back into the esophagus—the tube that carries food from your mouth to your stomach, it can cause a burning sensation called acid reflux, medically termed gastroesophageal reflux disease (GERD) or heartburn.

This backflow occurs because the valve containing the acids (the lower esophageal sphincter) weakens or relaxes when it shouldn’t. After drinking water, it travels down the esophagus into the stomach.

People with acid reflux usually already have excessive acid in their stomachs. So, as water enters, it further increases the production of these fluids and increases pressure inside the stomach, especially near weakened sphincter regions.

With more acids circulating in the stomach and additional force pushing upwards, some leak back across the weakened valve into the lower part of the esophagus. This burns and irritates the lining, which is not protected against the harsh acids.

The nerves in the esophagus detect this burning sensation and signal to the brain that something is wrong. The brain then triggers the body’s protective nausea reflex response, which explains the sudden discomfort in your stomach.

You have an electrolyte imbalance.

After intense yard work or exercise, chugging lots of water certainly hits that hydration sweet spot. But moments later, you’d probably be sorry you did. And if you’re an athlete, you may believe that overhydration will help you perform better or prevent dehydration. However, that’s often not the case.

Your body can only handle so much water at once. When you drink too much of it, the excess prevents your kidneys from removing it from the body fast enough. Water buildup in the body dilutes vital electrolytes like sodium, potassium, magnesium, chloride, and calcium.

The body needs a balance of these nutrients to maintain healthy blood, heart rhythm, muscle, and other essential functions. However, drinking too much water throws these elements out of whack and causes levels to drop drastically. This often results in an imbalance of electrolytes in the body linked to nausea and vomiting, muscle weakness, and spasms or cramps. In severe cases, symptoms may include headaches and mental confusion, seizures, unconsciousness, and even coma.

Learn more: 15 Benefits of Drinking Water and How Much You Need to Drink

Your stomach is already full.

Downing one or more large containers of water after a heavy meal is simply asking for trouble. Your stomach is already full, trying to break down all that food, so you’re making things worse by adding water.

While your stomach likely won’t explode, overfilling it causes its muscles to stretch beyond their normal limits. The vagus nerve, which handles communication between your gut and brain, warns that the stomach is full and you’re likely about to vomit to release some pressure. This sensation of fullness can trigger feelings of nausea as your stomach signals that it’s overwhelmed.

Your stomach is empty.

Drinking water on an empty stomach can also backfire. When you haven’t eaten in a while, your stomach usually becomes more sensitive to changes. As a result, it may perceive the sudden water intake as food and release gastric enzymes to digest it. Without food for the stomach to break down, the incoming water stimulates the rapid production of stomach acids, causing irritation and nausea symptoms instead.

You are dehydrated.

This may sound ironic, but being dehydrated can make you feel nauseous after drinking water. When there isn’t much fluid in your stomach, the mucus protecting the lining becomes thinner. Without enough mucus to cushion the stomach lining, any liquid you drink can directly irritate sensitive inner surfaces and make you queasy as your body’s way of signaling discomfort.

Besides, drinking water after being dehydrated causes the water to enter the bloodstream to help rehydrate your cells quickly. This quick shift in fluid levels can upset the delicate balance of electrolytes and other substances, making your stomach uneasy.

Learn more: Signs of Dehydration in Children and Adults | How Long Does The Body Take to Digest Water?

You are allergic to something in the water.

Sometimes, stomach discomfort occurs due to what’s in the water you drink—not necessarily the water itself. For instance, microbes like bacteria, viruses, and parasites can cause gastrointestinal issues in some people, including nausea, vomiting, and diarrhea. This is especially common in those with sensitive stomachs.

Besides, some water sources may contain chemical additives like chlorine and fluoride. While these substances are generally safe at regulated levels, high concentrations or sensitivity to these chemicals could lead to feelings of nausea.

Other times, water can pick up traces of minerals like calcium and magnesium that can make you feel a bit queasy after drinking the water.

Related: The 12 Most Dangerous Contaminants Found in America’s Water Supply | Manufacturing and Pharmaceutical Contaminants in Drinking Water

You drink water while lying down or shortly afterward.

If you drink a lot of water while standing or sitting upright, gravity pulls the liquid straight into your stomach. But if you lie flat or bend over shortly after, that water sloshes around in your stomach before settling.

Having a large amount of water circulating in your stomach may cause the water to splash toward the opening of the stomach and trigger a sensitive nervous reflex called the vagal response. This reaction protects against choking or inadvertent vomiting but may also cause you to feel nauseous.

Furthermore, the “tummy turbulence” caused by shifting position soon after drinking water may confuse fluid pressure sensors in the brain and inner ear. As a result, you may experience motion sickness or vertigo symptoms, which may translate to nausea.

So, How Do I Stop Feeling Nauseous After Drinking Water?

We all need water to survive, but sometimes we may feel stomach-sick after drinking it. Here are some possible ways to prevent or reduce this effect:

  • Don’t chug a tremendous amount of water all at once. Take smaller sips over time instead. This gives your stomach more time to adapt and makes you less likely to experience backflow of stomach contents into the esophagus. Gulping more than your body can comfortably process at once is never a good idea.
  • Avoid drinking too much water on a full stomach. Having a full stomach plus a surge of water can increase pressure and the chance of reflux. It’s better to drink moderately and consistently between meals. Allow at least 30 minutes for your stomach to digest some of its content and make space for more before drinking more fluids. And take slow sips instead of taking massive gulps.
  • Stand or sit upright while drinking and for at least 10-15 minutes afterward. Staying vertical aids gravity in keeping stomach contents where they belong. Conversely, lying flat right after drinking water permits easier backwash of liquid and acid.
  • Eat smaller, low-acid meals 4-5 hours before bedtime and keep your upper body and head elevated while sleeping. This helps keep acids from flowing back into your esophagus while you sleep.
  • Try to drink enough water throughout the day to prevent dehydration. Filling a reusable bottle with filtered water is a great way to stay hydrated on the go. If you’re at home most of the day, fill several glasses at the tap and hydrate.
  • Filter your water. Drinking water tainted with chlorine, fluoride, bacteria, and other contaminants and impurities may give you an upset stomach, especially if the concentrations are above average. If these elements trigger that post-drink nausea feeling, filtering your water is the most effective way to remove them.

How do I know if what’s in my water is causing my nausea issues?

Ingesting toxins is just one reason you may feel nauseous after drinking water. Therefore, it’s best to find out if your water is the culprit before expecting a filter to solve your nausea issues.

While a water quality report will give an overview of the water quality in your area, having your water tested at a certified laboratory will tell you exactly what’s in your water that’s likely causing you to feel nauseous. Usually, laboratories are equipped to evaluate water for a broad range of contaminants, impurities, and other quality metrics. Purchase a water test kit, submit a water sample to the laboratory, and await the results.

Learn more: How to Read Your Water Quality Report: Helpful Tips and Expert Advice | 10 Common Problems a Water Test Can Detect in Tap Water

The Best Water Filter to Help Prevent Nausea

If your water test results reveal the presence of chemicals, microbes, heavy metals, or other unwanted elements, we recommend investing in a water filtration system for your home.

Home water filter systems come in all shapes and sizes, each designed to address different contaminants and for other purposes. However, an under-counter water filter is an excellent choice if you only want filtered water directly from the sink.

Unlike pitchers or fridge filters that only purify small batches of water manually, under-counter units connect directly to the plumbing under your kitchen or bathroom sink. From there, it conveniently outputs clean filtered water on demand.

Under-sink systems like the Springwell SWRO Reverse Osmosis Water Filters deliver up to 75 gallons of clean, great-tasting filtered water daily. With multi-stage configurations, these systems remove a broad range of potential nausea-triggering contaminants from tap water. Plus, they require little maintenance—only occasional cartridge replacements every 6-12 months, depending on use.

Springwell offers a unique line of premium water filtration systems designed to remove unwanted materials from your water and improve its overall quality. If you want to learn more about our under-counter reverse osmosis systems or need help finding the most suitable one for your needs and budget, call us today at 800-589-5592 or message us via our contact page.

Final Thoughts

We all need water to stay hydrated, but how we hydrate and the quality of the fluid is just as important. Many people find that after drinking water, they experience mild stomach discomfort. This often results from drinking too much, too fast, having acid reflux, drinking water on a full or empty stomach, or an electrolyte imbalance in the body.

The good news is that with some simple adjustments to your drinking habits, you can enjoy water without the upset stomach symptoms it sometimes brings. For example, sipping your water in smaller portions instead of gulping it down all at once allows your stomach to adapt to the intake. It also helps avoid drinking large volumes on an empty or full stomach.

Testing your drinking water for contaminants that could irritate your stomach would also be a smart move. If detected, investing in a quality whole house water filtration system or under-counter water filter could help remove these pollutants, bringing you clean, refreshing filtered water. However, if your nausea symptoms persist despite changing your hydration habits or filtering your water, please seek advice from your doctor.