By Dr. Zafer Husami, Consultant Nephrologist, Mediclinic Middle East – Dubai
Peace be upon you and God’s mercy and blessings.
Ramadan is a sacred and deeply meaningful time. For many patients living with kidney disease, fasting is a sincere spiritual intention. However, fasting can affect hydration, blood pressure and metabolic balance, all of which are closely linked to kidney function.
In this article, I share comprehensive guidance for patients with kidney conditions who are considering fasting during Ramadan.
Important Note
Not all medical recommendations regarding fasting in kidney disease are supported by strong scientific evidence. Some are based on available studies, while others are drawn from more than thirty years of clinical experience in nephrology. Each patient’s situation is unique, and decisions should always be individualised.
General Recommendations for All Kidney Patients During Ramadan
Before fasting, every patient with kidney disease should consult their treating physician. The medical assessment should include the stage of kidney disease, the stability of kidney function, and whether complications such as hypertension, electrolyte imbalance or heart failure are present.
Hydration is central to safety during Ramadan. If there is no medical contraindication, patients should drink adequate fluids between iftar and suhoor. Fluid intake should be distributed gradually over several hours rather than consumed in large amounts at once. Avoiding dehydration is essential, as it may worsen kidney function, lower blood pressure and increase creatinine or potassium levels.
Medication review is equally important. Some medications, including antihypertensives, diuretics and diabetes treatments, may require dose or timing adjustments during Ramadan. However, medications must never be stopped or altered without medical advice.
Dietary care is also necessary. Patients should avoid excess salt, limit potassium- or phosphorus-rich foods when medically indicated, maintain moderate protein intake and avoid heavy or fatty meals at iftar. Blood pressure should be monitored regularly throughout Ramadan, and patients at risk of fluid retention should monitor their body weight daily.
Suhoor is an essential meal and should not be skipped. Delaying suhoor and choosing a balanced meal can help reduce thirst and support stability during fasting hours.
If severe dizziness, fainting, markedly reduced urine output, severe swelling, palpitations, profound weakness or extreme thirst occur, the fast must be broken immediately and medical care sought. It is important to remember that stopping the fast for medical reasons is not a failure. Religious concessions exist to protect health and life.
Special Recommendations for Kidney Patients with Diabetes
For patients with both kidney disease and diabetes, careful evaluation is required before fasting. Glycaemic control must be assessed, and fasting is discouraged in individuals with recurrent hypoglycaemia, unstable glucose control or advanced diabetic complications.
Insulin and certain oral hypoglycaemic agents may require adjustments in timing or dosage to align with iftar and suhoor. Self-adjustment without medical consultation is not permitted.
Blood glucose monitoring during fasting does not invalidate the fast and must be performed if symptoms such as dizziness, sweating, palpitations or sudden fatigue occur. The fast must be broken immediately if blood glucose falls below 70 mg/dL (3.9 mmol/L), rises above 300 mg/dL (16.7 mmol/L), or if symptoms of hypoglycaemia or hyperglycaemia develop.
Chronic Kidney Disease (CKD)
Patients with early-stage chronic kidney disease, specifically stages 1, 2 and stable stages 3A and 3B, may be able to fast under medical supervision. This is possible only if kidney function is stable, medications are appropriately adjusted, adequate fluids are consumed during non-fasting hours and regular follow-up is maintained.
In contrast, patients with stage 4 or stage 5 CKD who are not on dialysis are generally advised not to fast due to the high risk of kidney deterioration and complications.
End-Stage Kidney Disease (ESKD)
Patients receiving dialysis are generally advised not to fast. In carefully selected and clinically stable cases, some patients may be allowed to fast on non-dialysis days after thorough individual assessment and direct consultation with a nephrologist, with strict adherence to medical instructions.
Acute Kidney Injury (AKI)
Fasting is not recommended during episodes of acute kidney injury. These patients often require hospital admission, intravenous fluids and intravenous medications such as antibiotics. Fasting should be postponed until full recovery and stabilisation of kidney function.
Kidney Transplant Patients
Some kidney transplant recipients may be able to fast, but not all. The decision must be individualised following careful assessment by a nephrologist and transplant specialist.
Patients who may be considered suitable to fast include those who are more than one year post-transplant, have stable graft function, no recent rejection episodes, stable creatinine levels, good adherence to treatment and the ability to stop fasting if symptoms arise.
Patients advised not to fast include those less than one year post-transplant, those with suspected or confirmed graft rejection, unstable graft function, recurrent dehydration or hypotension, difficulty adhering to medication schedules or recurrent vomiting or diarrhoea related to immunosuppressive therapy.
With regard to tacrolimus, minor deviations from a strict 12-hour dosing interval, such as 11 and 13 hours, are generally acceptable in stable patients and do not usually result in dangerous fluctuations in drug levels. Consistency remains the most important factor. Immediate-release tacrolimus may be taken at iftar and suhoor, while extended-release formulations taken once daily at iftar may be suitable for selected patients under specialist supervision.
Kidney Stones and Fasting During Ramadan
Hydration is the most important preventive measure against kidney stone formation. The target is adequate urine output of at least 2–2.5 litres during non-fasting hours. Fluids should be distributed gradually from iftar until suhoor, rather than consumed all at once.
In cases of acute renal colic with severe pain, fasting is not recommended. Fasting may worsen pain, increase the risk of kidney function deterioration and raise the likelihood of infection or acute kidney failure. Fasting may only be reconsidered after complete resolution of symptoms.
For kidney stones causing partial or complete obstruction, whether painful or not, fasting is not recommended, particularly if hydronephrosis, rising creatinine, a solitary kidney or bilateral obstruction is present. Fasting should be avoided until the obstruction is relieved and kidney function stabilises.
In patients with asymptomatic (silent) kidney stones, fasting may be allowed if kidney function is stable and no obstruction exists, provided adequate fluid intake is ensured between iftar and suhoor. Excess salt and animal protein should be avoided. Urinalysis, kidney function tests and, when possible, renal ultrasound before Ramadan are recommended. Fasting must be stopped immediately if pain or reduced urine output develops.
For recurrent kidney stones, fasting may be possible only with extreme caution and strict preventive measures. At least 2.5–3 litres of fluid intake overnight is required, with a late, fluid-rich suhoor. Daytime heat exposure and strenuous physical activity should be avoided. In patients with frequent recurrent attacks, medical advice may favour breaking the fast.
Patients with kidney stones accompanied by associated risk factors, such as chronic kidney disease, a solitary kidney or advanced age, are generally advised not to fast due to the high risk of kidney deterioration.
Urinary Tract Infections and Kidney Infections During Ramadan
In uncomplicated lower urinary tract infections (Uncomplicated UTI), such as simple cystitis without fever, flank pain, vomiting or systemic deterioration, and with normal kidney function, fasting may be allowed. Adequate fluid intake of approximately 2–3 litres during non-fasting hours should be maintained, antibiotics should be taken at appropriate times and fasting must be stopped immediately if fever, flank pain, nausea or vomiting develop.
Complicated urinary tract infections (Complicated UTI), including those associated with fever, vomiting, flank pain, uncontrolled diabetes, kidney stones, urinary obstruction, pregnancy, prostatic enlargement or chronic kidney disease, generally make fasting inadvisable. Fasting should only be considered if the patient is completely stable and under close medical supervision.
In cases of acute pyelonephritis (kidney infection), fasting is absolutely contraindicated due to the high risk of dehydration, kidney function deterioration, sepsis and the frequent need for intravenous fluids and antibiotics.
Hypertension and Fasting During Ramadan
Most patients with well-controlled and stable hypertension can fast safely. However, patients with uncontrolled blood pressure, a recent stroke or heart attack, unstable heart failure or those requiring multiple daytime medication doses require individualised assessment and may be advised not to fast.
Conclusion
Fasting during Ramadan is a profound act of worship. At the same time, preservation of health and life remains a fundamental principle. Each patient with kidney disease must be assessed individually, and no single recommendation applies to all.
If you are living with kidney disease and are considering fasting, consult your treating physician well in advance. A carefully planned and medically guided approach can help ensure that both your health and your spiritual intentions are protected.
May you have a safe and blessed Ramadan.