Why Do I Feel So Sick After Drinking Water?

If drinking tap water made you feel sick, you’re not alone. 

While feeling nauseous from tap water isn’t the norm, there are a variety of reasons why it happens. And it’s not exactly a rare occurrence.

The cause could be as simple as a biological response to hunger, acid reflux, or excess chlorine. In this article, I’ll cover several of the common causes, symptoms, and remedies if this is happening to you.  

5 Common Reasons Why Water Causes Nausea

I’ll quickly caveat this list by saying that this list isn’t comprehensive, and I’m no substitute for your doctor. We will cover the most common causes of nausea from tap water, but every person (and water supply) is unique. Think of this article as a signpost or a starting point,

Chlorine Levels 

If you’ve just moved to a new address, you may be surprised at how your body responds to the tap water. Depending on the contaminants in your new location and chemical treatments applied by the utility company – your new water may be tough to stomach.

Chlorine (and Chloramine) are two of the most common public water additives. These compounds are helpful on a public health level because they are used to remove viruses, bacteria, and other harmful microorganisms from the water supply. According to the CDC, 4 milligrams of chlorine per liter of water is safe for drinking. 

At the same time, if the chemical density is high, it may cause a gag reflex. Especially if you’re not accustomed to the distinctive flavor.

Fortunately, if the problem is chlorine content then the solutions are simple and many. Nearly any under-sink water filter will knock out the problem in no time.


Believe it or not, dehydration can make you feel nauseous. Especially if you’re taking large gulps of water. Let me explain.

Dehydration happens when the body loses more fluid than it takes. There are several reasons:

  • Sweating a lot through exercising or due to the hot weather
  • Throwing up due to food poisoning 
  • Diarrhea 
  • Drinking alcohol just before bedtime. 

When your body is dehydrated, you may feel fatigued, dizzy, and have a dry mouth or tongue. Dark urine is a tell-tale sign of dehydration, as is not urinating often enough.

Per American Family Care, when you’re dehydrated, your body doesn’t have enough fluids. This causes overheating and may hamper the proper functions of your body.

If this sounds like you, try taking a few sips of water in short intervals. Don’t drink too much water too fast. It can cause your stomach to be too full too soon, leading to feelings of nausea. 

Foods like celery, watermelon, and cucumber are also good sources of water. 

If your child is dehydrated and refuses to drink water, try popsicles or fruit juice. 

The best treatment is prevention. According to Harvard, you should drink 13 cups of water daily if you’re a man. If you’re a woman, drink 9 cups every day.  (1 cup = 8 ounces).  In most cases, this should keep away dehydration. 

Full Stomach

It’s possible to feel nauseous if you’re drinking water immediately after a large meal.

Why? When you add water to the food, the stomach stretches. That’s why you may feel sick. 

Avoid taking sips of water between bites. This slows down your digestion process. That’s because the water dilutes the enzymes responsible for digesting our food. 

Slower digestion means food stays longer in the stomach. This causes your stomach to feel fuller. 

The stomach in an adult has a capacity of 2.5 ounces when empty and can stretch to hold up to a quart of food, as per Healthline. A quart is equal to 4 cups or 32 ounces of food and drinks. 

To put this in perspective, a standard-size coffee is equal to 8 ounces. Add a cup of rice or pasta to that, another cup of fish or meat or alternatives, and a cup of fruit and veggies.

That’s the most your stomach can take at a time. If you add water on top, you will feel nauseous! It’s best to stop eating when you are beginning to feel satiated. 

You’re Hungry or Have Acid Reflux

A simple case of hunger can make you feel sick after drinking water. Why? Well, your body has no food in it and is low on energy. It’s also ready to release digestive juices. 

As there is no food to break down into energy, your stomach tries to digest water.

And that makes you feel like throwing up. 

According to Manipal Hospitals, if you drink water first thing in the morning, you regulate the digestive system and flush out toxins. But this may cause you to feel nauseous. 

Instead, take little sips of water throughout the day. Avoid drinking whole glasses at a go. Plus, have a nutritious meal or snack to make you feel better. 

Acid reflux can also make you feel nauseous after drinking water. It’s a condition where food travels back to your throat from the stomach. 

Avoid going to bed immediately after meals or snacking right before bedtime. This should prevent acid reflux. 

Why Does Drinking Water Make Me Feel Nauseous When Pregnant?

There are a few common reasons for water nausea among pregnant women, that won’t necessarily apply to the general population.

Hormonal Changes

When you’re pregnant, the body produces a pregnancy hormone. This is called human chorionic gonadotropin or hCG. According to WebMD, this hormone causes you to feel nauseated after drinking water.

You’ll have higher levels of this hormone in your body in the first trimester. But as your pregnancy progresses, the levels come down. That’s why you will probably feel less nauseated when drinking water. 

Change in Taste

Because of the broad hormonal changes during pregnancy, you may also develop an aversion to the taste and smell of certain foods or drinks. 

Does water make morning sickness worse? Not necessarily, but it certainly doesn’t help when you’ve developed a dislike for the taste of plain water.

If this sounds like you, a decent adsorption water filter may serve you well. But you can also try swapping out tap water for coconut water, fruit juice, or even herbal tea.

For some pregnant women, the temperature of their tap water also makes a big impact on their comfort level in drinking it. Too hot or too cold may cause discomfort or nausea.

Drinking Water on a Full or Empty Stomach

When you’re pregnant, you’re already uncomfortable, thanks to the weight increase and higher water content in your body. Drinking water on a full stomach will stretch its capacity and make you feel sick. 

On the other hand, having water on an empty stomach will trigger the release of digestive juices. When there’s no food present in your system, drinking water can make you queasy.

So, avoid drinking water on a full or empty stomach when you’re pregnant. 


Can you be sensitive to tap water?

Yes, you can be sensitive to tap water. You may have high water sensitivity. This is a condition where you are sensitive to elements that are present in tap water. 

Should I drink water if I feel really nauseous?

It depends on why you’re feeling nauseous. If you have dehydration or electrolyte imbalance, drink water even if you are feeling sick. However, if you’re having acid reflux or if you have overeaten, drinking water will make you even more nauseated. 

How can I drink water without throwing up?

Start by taking small sips through a straw. If you still feel like throwing up, add some lime or lemon juice to the water or any fruit juice you like. You can also try flavored water.