Can Drinking Water Make You Nauseous? How Contaminants Trigger Gut Symptoms

Contaminated water can make you feel very sick. Bacteria, parasites, and viruses in drinking water can cause nausea, vomiting, stomach cramps, and diarrhea, sometimes within hours of exposure.

Common culprits include pathogens such as E. coli, Cryptosporidium, and Giardia, which may enter water through agricultural runoff, failing septic systems, or inadequate treatment. These microorganisms irritate the lining of the gut and can lead to acute gastroenteritis, often affecting multiple people in the same household at once.

Contaminants are not always biological. Excessive levels of metals like copper or lead, or high concentrations of certain minerals or disinfectant by‑products, can also upset your stomach. Some people are particularly sensitive and notice nausea, metallic taste, or a “chemical” smell even when levels are still within basic regulatory limits.

Look for patterns to decide if water quality might be the cause. Do you feel sick only when drinking water at home, but fine when you drink bottled water or water at work? Did nausea begin after a move, plumbing work, flooding, or a change in your local supply?

You can usually start with your local water quality report, then consider an at‑home test kit or a professional laboratory test (especially if you rely on well water). If tests show problems, using certified filters, bottled water, or appropriate disinfection steps can dramatically reduce symptoms.

If your water tests normal and you still feel nauseous after drinking, there may be a different reason. Check out our full breakdown of 8 Reasons You Feel Nauseous After Drinking Water—And How to Avoid It.