Immunotherapy and Blood in Urine: What to Know

Yes, blood in the urine (hematuria) can occur during cancer immunotherapy, though it’s not among the most common side effects. Certain immune checkpoint inhibitors list hematuria or urinary symptoms among potential adverse events, and some products flag kidney-related problems where blood in urine may appear. ^{[1] [2]}

How immunotherapy can lead to hematuria

• Immune-related kidney inflammation (nephritis): When the immune system attacks kidney tissue, you may see decreased urine output, changes in urine amount, or blood in the urine. These kidney warning signs are described for checkpoint inhibitors like pembrolizumab. ^[1]
• Urinary tract infection (UTI) susceptibility: Treatment can coincide with UTIs, which commonly cause burning or pain with urination and sometimes visible blood in urine. Patient education for nivolumab clearly highlights UTI symptoms including blood in urine. ^[3]
• Bladder irritation (cystitis): Cancer treatments can irritate the bladder lining and trigger urinary frequency, urgency, and occasionally bleeding. Practical guidance for managing treatment‑related bladder irritation recognizes this problem. ^[4]

How often does hematuria happen?

• Reported in urothelial cancer trials with pembrolizumab: Safety summaries show hematuria occurring among treated participants, indicating it is an observed adverse event, though not the most frequent one compared with other side effects. ^{[5] [2]}

When to seek urgent care

• Don’t ignore visible blood in urine; seek prompt medical evaluation. Authoritative patient guidance recommends contacting a clinician whenever urine appears red, pink, or cola‑colored, even if you are unsure whether it is blood. ^{[6] [7]}
• Go urgently if you have fever, nausea/vomiting, severe flank/back/abdominal pain, inability to urinate, or passing blood clots, as these may suggest infection, obstruction, or significant bleeding that needs immediate treatment. ^{[8] [9]}

Practical coping steps

• Call your oncology team early: Report new urinary symptoms (pain or burning with urination, urgency, increased frequency, lower abdominal or pelvic pain, fever) or any change in urine color. These signs can point to UTI or kidney problems during immunotherapy. ^{[3] [1]}
• Hydrate well unless your clinician advised fluid restriction: Adequate fluids can help reduce bladder irritation and support kidney function. General bladder care guidance during cancer treatment emphasizes supportive measures. ^[4]
• Avoid bladder irritants: Limit caffeine, alcohol, spicy foods, and artificial sweeteners, which can worsen urgency and discomfort. Bladder irritation education encourages practical lifestyle tweaks. ^[4]
• Track symptoms: Note onset, color (pink, red, tea‑colored), presence of clots, pain location, fever, or reduced urine output, and share this with your team. Detailed symptom reporting helps your clinicians judge severity and next steps. ^{[8] [6]}
• Follow testing and treatment plans: Your team may order a urinalysis, urine culture, kidney function blood tests, and imaging. If immune‑related nephritis is suspected, timely immunosuppressive therapy often improves symptoms, and clinicians monitor closely to ensure prompt recovery. ^[10]
• Medication guidance: If a UTI is diagnosed, antibiotics are typically prescribed; if immune‑mediated inflammation is confirmed, steroids or holding immunotherapy may be considered by your clinician. Consensus management guidance supports close monitoring and adjustment of immunotherapy when immune‑related adverse events are present. ^[10]

Related symptoms to watch

• Kidney warning signs: Unable to pass urine, markedly reduced urine volume, swelling/rapid weight gain, or dark urine warrant urgent contact. Checkpoint inhibitor materials list these kidney red flags. ^[1]
• Systemic signs: Fever or chills with urinary symptoms may indicate infection needing timely antibiotics. Standard patient advice flags fever, nausea, and vomiting as reasons to call promptly. ^{[8] [9]}

Bottom line

Blood in urine can occur during immunotherapy from infection, bladder irritation, or immune‑related kidney inflammation, and it deserves timely medical evaluation. Early reporting, avoiding irritants, staying hydrated, and working closely with your care team are practical ways to cope and stay safe. ^{[3] [1] [4] [6] [7]}