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Treatment and the treatment process

Monitoring urine

The amount, colour and content of urine say a lot about kidney function and the body’s fluid balance. During treatment it can be tracked in simple ways.

Last updated: ~2 min read
On a dark navy background, softly glowing teal kidneys with a fine golden stream flowing down from them.
Figure 1.The kidneys filter blood and make urine.

01Short answer

Watching urine matters in leukemia treatment for several reasons. During intensive hydration and when tumour lysis risk is high, the team needs to be sure the kidneys are removing enough fluid, so "intake and output" is recorded (fluid drunk and infused versus urine). Some medicines affect the kidneys or bladder: cyclophosphamide and ifosfamide can cause haemorrhagic cystitis (bleeding inflammation of the bladder), and certain antibiotics and antifungals affect kidney function. A urine test shows infection, blood and protein, while creatinine in the blood reflects how well the kidneys filter.

02Simple explanation

The kidneys are a filter. They clean the blood and remove extra water as urine.

Amount. Very little urine can mean the kidneys are struggling.

Colour. Dark can mean too little fluid; red can mean blood.

Records. If the team asks, measure and write down your urine.

03Scientific explanation

Urine output depends on the balance between filtration in the glomeruli and reabsorption in the tubules. Oliguria (a sharp fall in urine) can be an early sign of acute kidney injury.

Medicine effects: acrolein, a breakdown product of cyclophosphamide and ifosfamide, can damage the bladder lining; hydration and mesna are used to prevent this. Methotrexate can crystallise and harm the tubules; aminoglycosides, amphotericin B, vancomycin and calcineurin inhibitors are nephrotoxic.

Tests: urinalysis (specific gravity, pH, protein, blood, white cells, nitrites), urine culture, sometimes urine electrolytes and 24-hour volume; in the blood, creatinine and urea.

04What happens in the body?

How do the kidneys work?

A very large volume of blood passes through the kidneys every day. They keep what the body needs and remove extra water, salts and waste as urine.

Why measure urine?

During intensive infusions, comparing fluid in with fluid out shows the kidneys are keeping up and fluid is not building up.

A clean, clear, empty measuring jug on a bathroom shelf in cool light.
Figure 2.Measuring urine helps track fluid balance.

What does colour tell you?

Pale straw usually means good hydration. Dark urine can mean too little fluid, and pink or red can mean blood; some medicines also colour the urine.

A row of abstract glass droplets shading from pale straw to deep amber.
Figure 3.Urine colour gives clues about hydration.

05How urine is tracked

A simplified outline.

Collecting — In a special container.1CollectingIn a special container.
Recording — Amount and time.2RecordingAmount and time.
Testing — Urine and blood tests.3TestingUrine and blood tests.
Reporting — Any changes.4ReportingAny changes.
Kidneys protectedProblems seen early.
Fluid balanceIntake matches output.
Regular checksEspecially in intensive treatment.

06What to look out for in urine

ChangePossible causeWhat to do
Very little urineToo little fluid, kidney problemTell your team
Dark colourDrinking too little, dehydrationCheck the fluid plan with your team
Pink or redBlood, sometimes medicine colourTell them straight away
Burning, urgencyInfection, cystitisNeeds checking
Foamy urineSometimes proteinTell your team

* This table does not diagnose anything; the team always assesses changes.

07Key terms

Urine output
How much urine is passed.
Oliguria
A sharp fall in urine output.
Haemorrhagic cystitis
Bleeding inflammation of the bladder.
Creatinine
A blood substance that reflects kidney function.
Urinalysis
A laboratory test of urine.
Intake and output
A record of fluid entering and leaving the body.

08Key points

  • Urine says a lot about kidney function.
  • Urine may be measured during intensive treatment.
  • Report blood in the urine straight away.
  • Some medicines change urine colour — ask.
  • Burning and fever may mean infection.
  • Record measurements accurately and on time.

09Frequently asked questions

My urine turned orange — is that dangerous?

Some medicines (such as daunorubicin and doxorubicin) briefly turn urine reddish, but always tell your team.

Why measure urine at night too?

All urine is collected to know the total daily volume.

Will I need a urinary catheter?

Usually not; only in special cases, such as accurate measurement when very unwell.

I drink a lot but pass little — why?

This can mean fluid is being held in the body or the kidneys are struggling; tell your team.

10Questions for your doctor

Take these questions to your appointment. The ones you save are collected on the “My questions” page and stay on this device only.

  1. My urine turned orange — is that dangerous?

  2. Why measure urine at night too?

  3. Will I need a urinary catheter?

  4. I drink a lot but pass little — why?

My questions

12Sources

  1. National Cancer Institute (NCI). Urinary and Bladder Problems and Cancer Treatment
  2. MedlinePlus. Urinalysis
  3. MedlinePlus. Urine 24-hour volume
  4. MedlinePlus. Creatinine blood test
  5. National Cancer Institute. Immunotherapy Side Effects
  6. American Cancer Society. Typical Treatment of Acute Myeloid Leukemia (Except APL)
  7. NHS. Chemotherapy
  8. MedlinePlus (U.S. National Library of Medicine). Central venous catheters - ports
  9. National Cancer Institute (NCI). Recurrent Cancer: When Cancer Comes Back
  10. Centers for Disease Control and Prevention (CDC). Preventing Infections in Cancer Patients
Medical disclaimerThis information is for educational purposes only and does not replace medical advice.
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