Can Hard Water Cause Kidney Stones?

Posted by Alerna Kidney Health on

  • Hard water contains higher mineral content, primarily calcium and magnesium, due to geological factors like limestone and chalk formations.
  • Kidney stones form when minerals in urine crystallize. Types include calcium oxalate, uric acid, and struvite stones.
  • While research is ongoing, studies suggest an association between high mineral intake from hard water and kidney stone risk. Hard water's role in kidney stone formation is complex; genetics, diet, and lifestyle also play crucial roles.
  • Balancing hydration, diet, and consulting healthcare professionals are essential in supporting kidney health and minimizing stone risk.
  • Some individuals explore supplements like chanca piedra for potential kidney stone prevention and potassium citrate supplements to help manage urine pH and prevent stone formation.

In our quest for optimal health, we often explore various factors that can impact our well-being. One such factor that has gained attention in recent times is the quality of the water we consume. Particularly, there have been concerns about whether hard water could potentially contribute to the formation of kidney stones.

In this article, we'll dive deep into the topic, exploring the relationship between hard water and kidney stones while providing valuable insights to health-conscious individuals seeking natural ways to prevent or cure uric acid-related issues.

What Do We Mean by "Hard Water"?

Before we delve into the impact of hard water on kidney stones, let's first understand what hard water actually is.

Hard water is characterized by its high mineral content, primarily consisting of minerals like calcium and magnesium. These minerals are naturally present in the Earth's crust and can find their way into our water sources as they flow through mineral-rich rock formations.

The hardness of water [1] is typically measured in terms of grains per gallon (gpg) or milligrams per liter (mg/L) of minerals. Water is categorized into varying degrees of hardness:

  • Soft Water (0 to 60 mg/L): Contains a low concentration of minerals, particularly calcium and magnesium. Soft water tends to be more "slippery" and can create more lather with soap.
  • Moderately Hard Water (61 to 120 mg/L): Contains a moderate level of minerals. This type of water can still be used effectively for most purposes without causing significant issues.
  • Hard Water (121 to 180 mg/L): Contains a higher concentration of minerals, primarily calcium and magnesium. Hard water can create mineral deposits, soap scum, and other buildup on surfaces.
  • Very Hard Water (more than 180 mg/L): Contains a very high concentration of minerals. Water of this type can lead to more significant scaling and buildup issues.

Where Is Hard Water Commonly Found?

faucet water

Hard water is not uncommon and can be found in various regions around the world. It's often the result of water sources flowing through limestone, chalk, or gypsum deposits.

Many households, especially those dependent on well water or certain municipal sources, might find themselves dealing with hard water issues.

Geological Factors

Limestone and Chalk Regions: Water sources that flow through limestone and chalk geological formations tend to pick up significant amounts of calcium and magnesium. These minerals dissolve into the water, leading to the hardness of the water.

Gypsum Deposits: Gypsum is another mineral that can contribute to water hardness. Areas with gypsum-rich soil, like parts of the southwestern United States, might have hard water due to the dissolution of gypsum into the water sources.

Well Water

Many households and communities rely on well water as their primary water source. Depending on the geological characteristics of the area, well water can often be hard [2]. Wells that tap into underground aquifers passing through mineral-rich rock formations are more likely to yield hard water.

Municipal Water Sources

Even some municipal water sources can have varying degrees of hardness, depending on the location. Some municipalities treat water to reduce hardness before distributing it to households, but in some cases, the hardness might still be noticeable.

Surface Water

Rivers and lakes can also be affected by the hardness of the water. If the water sources feeding into these bodies of water flow through mineral-rich regions, the accumulated minerals can contribute to the hardness of the surface water as well.

Global Distribution

Hard water is not limited to specific regions. It's found in both developed and developing countries across the globe. Different parts of the world have varying levels of mineral content in their water sources, leading to variations in water hardness.

How Do Kidney Stones Form?


To comprehend the potential link between hard water and kidney stones, it's essential to grasp how kidney stones form.

Kidney stones are solid deposits of minerals and salts that accumulate in the kidneys. These deposits can vary in size, ranging from tiny grains to larger, more painful formations.

Kidney stones are formed when certain substances in the urine, such as calcium, oxalate, and uric acid, become concentrated and crystallize.

Can Hard Water Cause Kidney Stones

The theory behind the potential link between hard water and kidney stones revolves around the excess minerals present in hard water, particularly calcium and magnesium. If hard water with elevated mineral content is consumed regularly, the surplus minerals might contribute to the formation of kidney stones.

It's important to note that kidney stone formation is a complex process influenced by a range of factors, including genetics, diet, hydration levels, and underlying health conditions. Some individuals might be more prone to kidney stone formation due to their genetic predisposition or specific medical history.

How Excess Minerals in Hard Water Might Impact Kidneys

Hard water's high mineral content could potentially contribute to the mineral buildup within the kidneys. If hard water is consumed regularly, the excess calcium and other minerals it carries might lead to the formation of calcium-based kidney stones.

This theory is based on the idea that the minerals in hard water might combine with substances in the urine, creating an environment conducive to stone formation.


Hard Water and Kidney Stones: What Does the Research Say?

kidney health

While the concept of hard water's contribution to kidney stones seems logical, the scientific community is still working to establish a solid connection. Some studies have explored this potential relationship.

For instance, a clinical trial [3] explored the association between the hardness of drinking water and the risk of developing kidney stones. The study analyzed data from 18 individuals who had idiopathic nephrolithiasis, and the results indicated that increased intake of calcium and magnesium from drinking water was linked to a higher risk of developing kidney stones.

Compared to both tap and soft water, hard water caused a 50% significant increase in urinary calcium concentration. It suggests that extra intake of soft water is preferable for a preventive approach to calcium nephrolithiasis and as a way to lower the risk of recurrence of calcium stones.

Comparing Water Sources: Is Soft Water a Better Option?

Given the potential concerns related to hard water, individuals might wonder if there's a better alternative. Soft water, which has a lower mineral content, could be considered as an option. Let's weigh the pros and cons of soft water:

The Pros and Cons of Soft Water


  • Reduced Mineral Content: Soft water contains fewer minerals, which might lower the risk of mineral accumulation in the kidneys.
  • Less Scale Buildup: Soft water is less likely to leave mineral deposits on faucets, pipes, and appliances.


  • Sodium Concerns: Some softening processes involve the use of sodium, which might not be suitable for individuals on sodium-restricted diets.
  • Taste Considerations: Soft water might taste slightly different due to the absence of certain minerals.

How about bottled and tap water?

In the quest for the best water source, it's worth considering both bottled and tap water options. Bottled water is often marketed as a purer alternative, but it's important to note that not all bottled waters are the same. Some might be sourced from natural springs, while others could simply be purified tap water. Similarly, tap water quality [4] varies depending on your location and the treatment processes in place.

Preventive Measures: Keeping Your Kidneys Healthy

Regardless of the water source you choose, there are several proactive steps you can take to promote kidney health and potentially reduce the risk of kidney stones:

Proper Hydration: Quality Over Quantity?

Staying properly hydrated is essential, but the quality of the water matters just as much as the quantity. Ensure you're drinking water that's clean and free from contaminants. If hard water is your primary source, consider filtration methods that can help reduce mineral content.

Diet Adjustments to Consider

A balanced diet plays a pivotal role in kidney health. If you're concerned about kidney stones, consider adjusting your diet to include foods that are lower in oxalate content, as high oxalate levels can contribute to stone formation. Additionally, consult a healthcare professional for personalized dietary recommendations.

Drinking Chanca Piedra: The Stone Breaker

Chanca piedra [5], a herb native to the Amazon rainforest, has gained attention for its potential benefits in supporting kidney health. Known as "the stone breaker," it has been traditionally used for its supposed ability to help dissolve kidney stones and promote their natural passage through the urinary tract. While scientific research on its efficacy is still evolving, some studies have shown promising results.

Using Potassium Citrate: Managing Urine pH

Potassium citrate [6], has been used as a preventive measure against kidney stone formation. This supplement is believed to help maintain appropriate urine pH levels, creating an environment that discourages the crystallization of minerals and salts that contribute to stone formation.

Regular Health Check-ups

Routine health check-ups are crucial for catching potential kidney issues early on. Regular urine and blood tests can provide insights into your kidney function and help you make informed decisions about your lifestyle and water consumption.

When to seek medical advice?

If you're experiencing persistent discomfort, pain, or other symptoms that could be indicative of kidney stones or related issues, it's imperative to consult a medical professional. Only a healthcare provider can accurately diagnose and recommend the appropriate course of action.


In the pursuit of a health-conscious lifestyle, understanding the potential impact of hard water on kidney health is valuable. While the direct link between hard water and kidney stones is still under investigation, being mindful of the mineral content in your water source and adopting preventive measures can contribute to your overall well-being.

Remember, hydration and diet choices play pivotal roles in kidney health, so make informed decisions that align with your unique needs and circumstances.

Hard Water and Kidney Stones: FAQs

Does hard water affect kidney stones?

Research suggests a potential link between high mineral intake from hard water and kidney stone risk, but the connection isn't definitively established.

What kind of water causes kidney stones?

The mineral content in water, especially calcium and magnesium, from sources like hard water, is considered a potential factor in kidney stone formation.

What is the best water for kidneys?

Clean, balanced water with an appropriate mineral content is generally beneficial for kidneys. Consultation with a healthcare professional is recommended.

Is soft water good for kidneys?

Soft water, with reduced mineral content, might be considered beneficial for kidneys due to potentially lower risk of mineral buildup, but the decision should be based on individual health needs and preferences.

Medical Disclaimer:

The information provided in this article is for educational and informational purposes only and should not be considered a substitute for professional medical advice, diagnosis, or treatment. Please consult with your healthcare provider before starting any new dietary supplement, especially if you are pregnant, nursing, have a medical condition, or are taking other medications. Never disregard professional medical advice or delay in seeking it because of something you have read in this article.


  1. of water hardness&text=General guidelines for classification of,mg%2FL as very hard.
  3. Bellizzi, V., De Nicola, L., Minutolo, R., Russo, D., Cianciaruso, B., Andreucci, M., Conte, G., & Andreucci, V. E. (1999). Effects of water hardness on urinary risk factors for kidney stones in patients with idiopathic nephrolithiasis. Nephron81 Suppl 1, 66–70.
  4. Schwartz, B. F., Schenkman, N. S., Bruce, J. E., Leslie, S. W., & Stoller, M. L. (2002). Calcium nephrolithiasis: effect of water hardness on urinary electrolytes. Urology60(1), 23–27.
  5. Pucci ND, Marchini GS, Mazzucchi E, Reis ST, Srougi M, Evazian D, Nahas WC. Effect of phyllanthus niruri on metabolic parameters of patients with kidney stone: a perspective for disease prevention. Int Braz J Urol. 2018 Jul-Aug;44(4):758-764. doi: 10.1590/S1677-5538.IBJU.2017.0521. PMID: 29617079; PMCID: PMC6092661.
  6. Krieger NS, Asplin JR, Frick KK, Granja I, Culbertson CD, Ng A, Grynpas MD, Bushinsky DA. Effect of Potassium Citrate on Calcium Phosphate Stones in a Model of Hypercalciuria. J Am Soc Nephrol. 2015 Dec;26(12):3001-8. doi: 10.1681/ASN.2014121223. Epub 2015 Apr 8. PMID: 25855777; PMCID: PMC4657843. patients%2C the addition of,to decrease recurrent stone formation.&text=In a randomized%2C double-blind,cit decreased recurrent stone formation.
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