Kidney Stones And Dehydration: Doctors Explain The Connection

Drinking water is good for our overall wellbeing. Thus, it goes without saying that dehydration can be harmful for our health. Among many diseases or conditions that can be triggered by dehydration, kidney stones are one of them. Yes, dehydration and kidney stones have a strong connection. Today, we will tell you all about it.

To get experts’ views on this, we reached out to Ms Edwina Raj, Senior Dietician, BSC, MSC RD, Aster CMI Bangalore, Dr Kishan A, Consultant – Nephrology, Aster CMI Hospital Bangalore and Dr Alok Kumar Pandey, Senior Consultant, Nephrology, Regency Health, Lucknow.

Can Dehydration Cause Kidney Stones?

As per research from the National Institutes of Health (NIH), dehydration is an important risk factor for kidney stones. The research further stated that one should drink enough water to have about two litres of urine output daily to prevent kidney stones and pay attention to their urine colour to know if the goal is being achieved or not. “Dark yellow urine is a sign of dehydration,” the research noted.

"Yes, dehydration can increase the risk of developing kidney stones because the body does not have enough water to dilute minerals and salts in the urine. When a person drinks less water, the urine becomes more concentrated, which allows substances like calcium, oxalate, and uric acid to stick together and form crystals that may gradually grow into kidney stones,” shares Edwina. 

“Drinking enough fluids helps the kidneys flush out these waste materials before they have a chance to form stones. People who live in hot climates, sweat a lot, or do not drink enough water during the day are more likely to experience dehydration. Dietitians often recommend drinking adequate water throughout the day so that urine stays light in colour, which helps support kidney health and reduce the risk of stone formation,” adds the expert.

ALSO READ - Where Do Kidney Stones Actually Hurt? Doctors Explain

How Dehydration Affects Kidney Stones?

Dehydration can worsen the symptoms of already existing kidney stones. Shedding more light on this, Edwina shares, “This is because the body does not have enough water to dilute the urine and help move the stone out of the urinary tract. When a person is dehydrated, the urine becomes more concentrated, which can irritate the kidneys and urinary tract and intensify the pain. Low fluid levels also slow down the flow of urine, which makes it harder for the stone to pass naturally. As a result, the stone may stay in the urinary tract longer and may cause more discomfort, burning during urination, or difficulty passing urine. Dietitians usually advise people with kidney stones to drink enough water during the day to support urine flow and help the stone pass more easily.”

Adding to this, Dr Pandey says, "If a person already has kidney stones, dehydration can make the situation worse. When urine is concentrated, more minerals may settle on the existing stone, causing it to grow larger. Dehydration can also increase the likelihood of pain episodes, blockages in the urinary tract, or even infections in some cases. Drinking enough fluids helps keep the urine diluted and may reduce the chances of the stone increasing in size."

Can Kidney Stones Go Away By Drinking Water?

Drinking enough water can help some small kidney stones pass naturally. Explaining this further, Edwina says, “It may not completely make all kidney stones go away. When a person drinks plenty of water, it increases urine production, which helps flush the kidneys and urinary tract and may push small stones out of the body through urine.”

The expert continues, “Water also helps dilute minerals and salts in the urine, which can prevent the stone from getting bigger and reduce the chance of new stones forming. However, larger stones may not pass only by drinking water and may require medical treatment or procedures to remove them. Regular water intake throughout the day is thus recommended to support kidney function and help the body clear small stones more easily.”

What Is The Role Of Water In Kidney Stone Prevention?

There’s a common notion that drinking water can help prevent kidney stones. As per NIH, it is indeed true. It has been mentioned that consuming sufficient water is crucial to preventing kidney stones. This, however, does not hold for those who have kidney failure and chronic kidney disease (CKD),as excessive water intake might create complications for them. Unless that is the case, many health experts recommend drinking six to eight glasses of water a day, it states. However, they emphasised consulting their physician to check how much water they should drink.

As per the National Health Service (NHS), one can prevent kidney stones from returning by aiming to drink up to three litres of water daily throughout the day. They shared the following tips for the same:

• Drink water, but drinks like tea and coffee also count.
• Add fresh lemon juice to your water.
• Avoid fizzy drinks.
• Do not eat too much salt.

Highlighting this, Dr Kishan shares, “Water plays a very important role in preventing kidney stones because it helps dilute the urine and reduces the concentration of minerals and salts that can form stones. When a person drinks enough water throughout the day, the kidneys produce more urine, which helps flush out substances such as calcium, oxalate, and uric acid before they can combine and form crystals. Adequate water intake also prevents the urine from becoming too concentrated, which is one of the main reasons kidney stones develop.”

Which Other Drinks Can Prevent Kidney Stones Fast?

Before we dive into some expert-backed drinks or fluids, other than water, which can help dissolve kidney stones, let us take a look at what studies have shown in this regard till now.

As per a 2020 study, published at the Saudi Journal of Biological Sciences, basil leaves, tested in rats, were shown to support kidney function (these findings are preliminary and based on animal studies only. They should not be taken as medical advice for human treatment). Traditionally, basil juice has been in use for digestive and inflammatory disorders. It contains antioxidants and anti-inflammatory properties. Another 2019 PubMed Central study, published at Lancet’s EBioMedicine journal, discovered that apple cider vinegar, which contains acetic acid, can help prevent kidney stones. The study notes that its consumption may help reduce the formation of kidney stones. Another 2019 study, published at the Journal of Pharmacy & BioAllied Sciences (conducted in rats) stated that celery extract can help break down kidney stones. However, it added that the results may not be the same for everyone. 

Shedding light on this, Dr Kishan shares, “No fluid can instantly dissolve kidney stones, but some drinks may help reduce the risk of stone formation and support the body in passing small stones more easily.” The expert lists down the same:

• Along with water, fluids like lemon water or citrus-based drinks may be helpful because they contain citrate, a natural substance that can prevent certain types of kidney stones from forming or growing.
• Coconut water and diluted fruit juices may also help maintain hydration, which supports urine flow and helps flush minerals out of the urinary system. 

“However, these fluids do not quickly dissolve existing stones, especially larger ones, and medical treatment may still be required. The most important step is drinking enough fluids daily to keep urine diluted and support overall kidney health,” adds the expert.

Which Drinks Should Be Avoided For Kidney Stones?

“People with kidney stones should avoid or limit certain drinks that may increase the risk of stone formation,” shares Dr Kishan. The expert lists down the same for us:

• Sugary soft drinks, especially those containing high sugar or certain additives, can increase the amount of minerals in the urine and raise the chances of stones forming.
• Drinks with high amounts of caffeine, such as strong coffee or energy drinks, may also lead to dehydration. If consumed in excess, it can worsen the risk of kidney stones.
• Some packaged fruit juices and sweetened beverages can contain high sugar levels, which may also contribute to stone formation.
• It is also better to limit drinks that are very high in sodium or artificial sweeteners. 

“Doctors usually recommend drinking plenty of plain water and choosing natural, low-sugar fluids to support kidney health and reduce the risk of stones,” says Dr Kishan A. 

"People who are prone to kidney stones should be mindful of the beverages they consume. Drinks that are high in sugar, such as sugary soft drinks and sweetened fruit juices, can increase the risk of stone formation. Excessive soft drink consumption may also contribute because it contains phosphoric acid. Energy drinks and high alcohol intake can lead to dehydration, which further raises the risk. The best approach is to focus on adequate water intake and consume other beverages in moderation," adds Dr Pandey.

When To Visit A Doctor For Kidney Stones

As per the Cleveland Clinic, around 80% of kidney stones pass on their own. The amount of time it takes to pass a kidney stone depends on its size and location. Their report mentions that smaller stones pass within one to two weeks, while larger ones may take about two to three weeks to completely pass. So, when to seek medical help for kidney stones? If one experiences severe, unbearable pain, fever with chills, vomiting, or blood in the urine, they should seek urgent medical care. Medical evaluation is important to check for blockages or infection.

ALSO READ - Can Kidney Stones Cause Blood in Urine? Causes, Signs & When to See a Doctor

The Final Word

Dehydration can increase the risk of forming kidney stones. This is because the body lacks enough water to dilute minerals and salts in the urine. Dehydration can also worsen the symptoms of already existing kidney stones. Thus, doctors recommend drinking plenty of water or citrus-based drinks and limiting sugary drinks to prevent kidney stones.