Can I Fast With Kidney Stones? Navratri, Ramzan and Karva Chauth

Patients ask me this every year, usually a few days before the fast begins, and usually hoping I will not say no.

For most people the answer is yes. The research on this is more reassuring than you might expect. But it depends heavily on which fast, what the weather is doing, and whether you currently have a stone sitting in your kidney or a history of them.

Here is the honest position for each of the three main fasts observed in India, plus who genuinely should not fast this year.

What the Research Actually Shows

A systematic review pooling ten studies and nearly ten thousand participants looked at whether fasting increases kidney stone risk. Seven of the nine Ramadan studies found no change in the rate of renal colic during the fasting month. The review concluded that fasting is unlikely to significantly increase the risk of kidney stones.

Two important qualifications sit alongside that.

Urine chemistry does change. Several studies found that urine becomes more concentrated during fasting hours, with measurable shifts in the substances that form stones. The chemistry moves in the wrong direction even when the clinical outcome does not.

Heat matters more than fasting. One study specifically concluded that high temperature, rather than fasting itself, drove the increase in renal colic presentations. A Saudi study found fasting patients were around twice as likely to present with a ureteric stone specifically when Ramadan fell in summer.

And the crucial limitation: these studies looked at general populations, not at people who already have a diagnosed stone. Someone with a known 6mm stone fasting in Delhi in June is not the average participant in that research.

So the summary is this. Fasting itself is not the danger. Fasting badly, in heat, with an existing stone, is.

Navratri

Nine days, twice a year, and the one where the food is more of a problem than the fluid.

Navratri vrat generally permits water and often permits fruit, milk, and specific flours. That means dehydration is manageable. The issue is what people eat.

Kuttu atta, buckwheat flour, is high in oxalate. So is rajgira, amaranth. These are the two staples of Navratri cooking and they are among the higher oxalate foods in the Indian diet. Eating them for nine consecutive days is a meaningful oxalate load for a calcium oxalate stone former.

Potato and sweet potato are also high in oxalate, and they appear in almost every vrat meal.

Peanuts are very high in oxalate, and sabudana khichdi is usually loaded with them.

Sendha namak is still salt. Rock salt is chemically sodium chloride with trace minerals. It does exactly what table salt does to your urinary calcium. The perception that it is a healthier salt does not apply here.

What is genuinely fine, and even helpful:

• Sabudana itself is low in oxalate. It is the peanuts that are the problem, not the sago.
• Milk, curd, paneer. Dairy is protective, because calcium taken with meals binds oxalate in the gut before it reaches the kidney. Navratri is one fast where the traditional food actually helps. See can kidney stone patients consume milk.
• Most fruits, coconut water, lemon water. Citrus provides citrate, a genuine stone inhibitor.
• Singhara atta is a reasonable alternative to kuttu if you want to reduce the oxalate load.

Practical plan for Navratri: keep fluid intake normal or higher, take dairy with meals rather than separately, go easy on peanuts and potato, alternate kuttu with singhara, and do not assume sendha namak means you can salt freely.

See the 10 foods that cause kidney stones and the role of diet in kidney stone formation and prevention.

Ramzan

Thirty consecutive days with no food and no water from dawn to dusk. This is the highest risk of the three, purely because of the fluid restriction.

For twelve to fifteen hours your urine concentrates, which is precisely the condition that favours crystal formation. The reassuring research above means this usually does not translate into more stones in the general population. It does not mean it is risk free for someone who already forms them.

The single biggest variable is the season. Winter Ramzan in India is considerably safer than summer Ramzan. Heat plus fluid restriction plus outdoor work is the combination that puts people in emergency departments.

How to fast more safely:

• Front-load fluid at suhoor. Do not treat it as a small meal before sleep. Aim to take a substantial volume of water in the pre-dawn window rather than a single glass.
• Spread intake across the whole non-fasting window, from iftar through to suhoor, rather than drinking heavily at iftar and stopping. Steady intake produces better urine dilution than one large volume.
• Track urine colour after iftar. If it is still dark several hours after breaking the fast, your total intake is too low.
• Limit caffeine at iftar. Tea and coffee in large amounts add a diuretic effect to a body already behind on fluid.
• Go easy on salt. Iftar food is frequently salty, and sodium drives calcium into the urine.
• Reduce outdoor exertion during fasting hours where you can, particularly in summer.
• Watch the weeks after Ramzan too. One study found an increase in renal colic admissions in the month after Ramadan rather than during it, suggesting a delayed effect.

See how much water you should drink to prevent kidney stones and why hydration is necessary for kidney health.

Karva Chauth

One nirjala day, no food or water from before sunrise until moonrise, typically thirteen to fourteen hours.

Because it is a single day, the cumulative risk is low. There is no realistic prospect of forming a new stone in fourteen hours. The risk is acute rather than chronic: if you already have a stone sitting in the kidney or ureter, a day of concentrated urine can be what triggers an episode of colic.

Karva Chauth also falls in October, which helps considerably compared with a summer fast.

Practical plan: hydrate well the day before rather than trying to catch up afterwards, take a good volume of water at sargi, avoid salty food at sargi since it will make you thirstier and raise urinary calcium, stay out of heat and heavy exertion during the day, and rehydrate steadily after moonrise rather than in one go.

The same approach applies to Nirjala Ekadashi, Shivratri, Jain upvas, and other single-day waterless fasts. Nirjala Ekadashi is the harder one, since it falls in June.

Who Should Not Fast This Year

Every major faith permits exemption from fasting on genuine medical grounds. If you fall into one of these groups, this is a conversation to have with your doctor and, if it helps, with your religious guide.

• An active stone episode, or a stone currently causing pain
• A known obstructing stone, or hydronephrosis on a recent scan
• Any sign of infection, particularly fever
• A DJ stent in place. Dehydration with a stent significantly worsens symptoms and bleeding. See DJ stents explained
• Recent stone surgery, within a few weeks
• A single functioning kidney or a transplanted kidney
• Chronic kidney disease or reduced kidney function. See 10 signs of chronic kidney disease
• Frequent recurrent stones that are not yet under control
• Pregnancy. See kidney stones in pregnancy
• Outdoor or heavy physical work during a summer fast

Your Medications During a Fast

This gets overlooked and it matters.

If you take potassium citrate, it is usually taken in divided doses through the day. During a waterless fast, that schedule has to be rearranged into the eating window rather than skipped.

If you take an alpha blocker to help a stone pass, it should not be stopped, and the timing may need adjusting.

If you take a thiazide diuretic for urinary calcium or blood pressure, fasting plus a diuretic increases the risk of dehydration and needs specific advice.

Do not reschedule or skip any of these on your own. Ask your doctor two weeks before the fast begins, not the night before.

Break the Fast If This Happens

Stop and seek medical help, regardless of the fast, if you develop:

• Severe flank or abdominal pain in the classic kidney stone pattern
• Fever or chills
• Persistent vomiting
• Little or no urine despite the fast having ended
• Visible blood in the urine

Every faith tradition permits breaking a fast in a medical emergency. An infected obstructed kidney can deteriorate within hours, and no observance requires you to risk that. See how to know when a kidney stone is serious.

After the Fast

If you have had more than one stone, the fasting season is a good prompt to find out why you form them, rather than managing each episode as it comes. That means composition analysis of any stone you pass and a metabolic evaluation of what your urine is doing across a full day. See what to expect during your kidney stone tests and how to avoid kidney stone recurrence.

Our kidney stone checker gives a quick indication of what your size and location typically require, and our kidney stone treatment page sets out the options including RIRS.

To discuss whether fasting is safe in your specific case, book a consultation with Dr. Deepanshu Gupta, ideally a couple of weeks before the fast rather than during it.

Frequently Asked Questions

Is fasting safe if I have kidney stones?

For most people, yes. A systematic review of ten studies found that fasting is unlikely to significantly increase kidney stone risk. The exceptions are people with an active or obstructing stone, infection, a stent, recent surgery, a single kidney, or reduced kidney function.

Does Ramzan fasting cause kidney stones?

Most studies found no increase in renal colic during Ramadan. Urine does become more concentrated during fasting hours, and the risk rises when Ramadan falls in summer, but fasting alone has not been shown to cause stones in the general population.

Can I keep Karva Chauth with a kidney stone?

Usually yes, if the stone is not obstructing and you have no infection, since it is a single day in a cooler month. Hydrate well the day before, avoid salty sargi food, stay out of the heat, and rehydrate steadily afterwards.

Is kuttu atta bad for kidney stones?

Buckwheat flour is high in oxalate, as is rajgira. For calcium oxalate stone formers, eating these daily for nine days of Navratri is a meaningful oxalate load. Alternating with singhara atta reduces it.

Is sendha namak better than regular salt for kidney stones?

No. Rock salt is still sodium chloride and affects urinary calcium the same way. The belief that it is a healthier salt does not apply to stone risk.

Can I drink water during Navratri if I have stones?

Navratri vrat generally permits water, and you should take full advantage of that. Keep intake normal or higher than usual across the nine days.

Should I stop my kidney stone medicines while fasting?

Never on your own. Potassium citrate, alpha blockers, and thiazides all need specific rescheduling into the eating window rather than being skipped. Ask your doctor at least two weeks before the fast begins.

When should I break a fast because of a kidney stone?

Immediately with severe pain, fever or chills, persistent vomiting, minimal urine output, or visible blood in the urine. All faith traditions permit breaking a fast in a medical emergency.

References

1. The association between renal stones and fasting: A systematic review. PubMed. https://pubmed.ncbi.nlm.nih.gov/32807286/
2. Lidawi G, Majdoub M, Asali M, Avidor Y, Rub R. Ramadan fasting and rates of admissions for renal colic due to urolithiasis: a retrospective case-control study. https://pmc.ncbi.nlm.nih.gov/articles/PMC11287717/