Not Passing Urine or — Passing Very Little

Several chemotherapy drugs are known to be nephrotoxic, meaning they can stress or damage the kidneys, and your oncology team will usually give extra precautions — such as intravenous fluids before each dose — when these are used. NCCN and ASCO guidance flags cisplatin and ifosfamide as drugs requiring particular kidney monitoring. Ask your oncologist which drugs are in your regimen and what monitoring is planned, rather than waiting to notice a symptom.

Drinking fluids can help if mild dehydration is the only cause, but do not try to manage this at home without speaking to your team first. If the cause is kidney injury rather than dehydration alone, extra fluids at home will not reverse it and will delay the assessment that can. Call your team and describe the change. They will tell you whether to come in or whether drinking more is the right first step.

Not necessarily. Chemotherapy doses are often calculated based on how well the kidneys are working, so a change in kidney function may affect the dose rather than stopping treatment altogether. The decision depends on how significant the change is and how quickly it responds to treatment. Reporting early is what keeps the milder options available — waiting makes the decision harder, not easier.

Your team will ask about your urine output, fluid intake, any swelling, and other symptoms. Blood tests to check kidney function and electrolytes will almost certainly be done the same day. If the results show kidney stress, you may be given fluids through a drip and kept in for monitoring. The aim is to find the cause quickly and act before the injury progresses.