Browse categories and answer follow-up questions to refine your symptom profile.
History
Urine output pattern
Urine output characterization
Oliguria definition
Adult urine output < 0.5 mL/kg/hour for 6 hours
Anuria definition
Adult urine output < 50 mL/day
Time course
Sudden onset hours
Progressive days
Baseline renal function and urine output
Prior creatinine trend
Chronic kidney disease history
OPQRST
Symptom anchors for associated complaints
Onset
Last normal void time
Abrupt after procedure or trauma
Provocation/Palliation
Worse with dehydration
Relief after catheterization
Quality
Suprapubic pressure
Flank colic pain
Region/Radiation
Flank
Groin radiation
Severity
Pain score
Functional limitation
Timing
Intermittent
Constant
Associated symptoms
Symptom clusters
Volume depletion
Poor intake
Vomiting
Diarrhea
Obstructive lower urinary tract symptoms
Hesitancy
Weak stream
Incomplete emptying
Dribbling
Nocturia
Infection symptoms
Fever
Chills
Dysuria
Flank pain
Systemic inflammation or autoimmune
Rash
Arthralgia
Hemoptysis
Cardiorespiratory congestion
Dyspnea
Orthopnea
Leg edema
Rhabdomyolysis clues
Myalgias
Dark urine
Malignancy or stone clues
Gross hematuria
Weight loss
Context and triggers
Precipitating events
Recent contrast exposure
CT contrast timing
Angiography timing
Recent surgery or anesthesia
Post op urinary retention risk
Hypotension episodes
Recent infection or sepsis
Suspected source
Antibiotic exposure
Exercise or prolonged immobilization
Crush or prolonged down time
Heat exposure
Pregnancy status
Positive test possibility
Preeclampsia symptoms
Alarm Features
Immediate threats
Resuscitation triggers
Shock physiology
SBP < 90 mmHg
MAP < 65 mmHg
Lactate elevation
Severe hyperkalemia concern
K 6.5 mmol/L or higher
ECG changes with elevated K
Pulmonary edema
Hypoxemia
Respiratory distress
Uremic emergencies
Encephalopathy
Pericarditis
Uncontrolled bleeding
Obstruction red flags
High risk obstruction features
Anuria with bladder distension
Suprapubic pain
Palpable bladder
Solitary kidney
Known nephrectomy
Transplant kidney
Bilateral obstruction risk
Known bilateral stones
Pelvic malignancy
Special populations red flags
High risk cohorts
Pregnancy
Hypertension
Headache or visual symptoms
Immunocompromised
Neutropenia
Transplant recipient
Anticoagulated
Gross hematuria with clots
Possible obstructing clot retention
Medications
Nephrotoxic and hemodynamic agents
Medication exposures
NSAIDs
Recent start
High dose use
ACE inhibitors
Recent dose change
Suspected renal artery stenosis risk
ARBs
Recent dose change
Volume depletion context
Diuretics
Overdiuresis risk
Recent escalation
Aminoglycosides
Gentamicin
Tobramycin
Vancomycin
High trough exposure
Concomitant piperacillin tazobactam exposure
Calcineurin inhibitors
Tacrolimus
Cyclosporine
Chemotherapy
Cisplatin
Ifosfamide
Allergic interstitial nephritis triggers
Hypersensitivity linked drugs
Beta lactams
Penicillins
Cephalosporins
Sulfonamides
TMP SMX
Sulfasalazine
PPIs
Omeprazole
Pantoprazole
Obstructive and retention promoting agents
Urinary retention risk medications
Anticholinergics
Oxybutynin
Tricyclic antidepressants
Opioids
Recent initiation
Dose escalation
Alpha agonists
Pseudoephedrine
Phenylephrine
Diet
Intake and hydration
Recent intake pattern
Poor oral intake
Nausea
Inability to drink
Excessive losses
Diarrhea
Vomiting
High protein intake
Catabolic state
Supplement use
High potassium intake context
Salt substitutes
Large fruit juice intake
Review of Systems
System checklist
Organ system symptoms
Constitutional
Fever
Weight loss
Cardiopulmonary
Chest pain
Dyspnea
Orthopnea
GI
Vomiting
Diarrhea
GU
Dysuria
Hematuria
Flank pain
Neuro
Confusion
Seizure
Skin and MSK
Rash
Myalgias
Collateral History and Family History
Collateral and inherited risk
Additional sources and inherited conditions
Collateral source reliability
Caregiver report
Medication list verification
Family renal disease
Polycystic kidney disease (Q61.2)
Alport syndrome
Early cardiovascular disease
MI or stroke before age 55 male relative
MI or stroke before age 65 female relative
Risk Factors
AKI susceptibility and exposures
Risk profile
Chronic kidney disease (N18.9)
Baseline eGFR reduction
Proteinuria history
Diabetes mellitus (E11.9)
Microvascular disease
Diabetic nephropathy history
Heart failure (I50.9)
Cardiorenal physiology risk
Diuretic dependence
Cirrhosis (K74.60)
Ascites
Hepatorenal syndrome risk
Sepsis or severe infection
Recent bacteremia
ICU stay
Obstructive uropathy risk
BPH (N40.1)
Pelvic malignancy history
Neurogenic bladder (N31.9)
Vascular risk
Atherosclerosis
Known renal artery stenosis
Pregnancy related risk
Preeclampsia (O14.9)
HELLP syndrome
Differential Diagnosis
Life threatening
Immediate risk diagnoses
Hyperkalemia with malignant arrhythmia
Bradycardia
Ventricular tachyarrhythmia
Urosepsis with obstructive uropathy
Fever with flank pain
Hypotension
Bilateral ureteral obstruction
Anuria
Hydronephrosis
Acute glomerulonephritis with pulmonary renal syndrome
Hemoptysis
Rapid creatinine rise
Thrombotic microangiopathy
Hemolysis
Thrombocytopenia
Acute renal infarction
Sudden flank pain
LDH elevation
Common
Common causes by category
Prerenal azotemia
Hypovolemia
Low effective arterial blood volume
Acute tubular injury or necrosis (N17.0)
Sepsis associated
Ischemic hypotension
Nephrotoxin exposure
Postrenal obstruction
BPH (N40.1)
Ureteral stone (N20.0)
Acute interstitial nephritis (N10)
Drug induced
Eosinophiluria possibility
Less common
Less common and mimics
Rhabdomyolysis (M62.82)
CK elevation
Pigment nephropathy
Hepatorenal syndrome
Advanced cirrhosis
Low urine sodium context
Cardiorenal syndrome
Decompensated heart failure
Congestive nephropathy
Renal artery stenosis with ACE inhibitor exposure
Refractory hypertension
Flash pulmonary edema
Bladder outlet obstruction from clot retention
Gross hematuria
Inability to void
Past Medical History
Baseline renal and urologic history
Relevant prior conditions
Chronic kidney disease stage
Prior eGFR baseline
Dialysis history
Prior urinary retention episodes
Catheterization history
Known BPH
Urolithiasis history
Prior obstructing stone
Prior stent placement
Renal transplant history (Z94.0)
Immunosuppression regimen
Prior rejection episodes
Recent hospitalization
Sepsis
Contrast studies
Physical Exam
Vitals and general
Global assessment
Vital sign patterns
Hypotension
Fever
Tachycardia
Volume status
Dry mucous membranes
Orthostatic changes
Capillary refill delay
Fluid overload
Elevated JVP
Crackles
Peripheral edema
Focused abdominal and GU
Abdominal and GU findings
Bladder distension
Suprapubic fullness
Suprapubic tenderness
Costovertebral angle tenderness
Unilateral
Bilateral
Genital exam when relevant
Phimosis
Paraphimosis
Rectal exam when indicated
Prostate enlargement
Prostate tenderness
Skin, joints, neuro
System clues to intrinsic renal disease
Rash patterns
Palpable purpura
Morbilliform rash
Joint findings
Synovitis
Arthralgia
Neuro uremia
Asterixis
Altered mental status
Lab Studies
Core AKI panel
Initial labs
BMP
Creatinine trend
Potassium
Bicarbonate
CBC
Leukocytosis
Anemia
Venous blood gas
pH
Lactate
Urinalysis with microscopy
Hematuria
Proteinuria
Casts
Urine culture when infection possible
Pyuria
Nitrites
Urine indices and interpretation
Urine chemistry patterns
Urine sodium
Low urine sodium supportive of prerenal states
Limitations in diuretic use
FENa
< 1 percent supportive of prerenal physiology
Unreliable with diuretics
FEUrea
< 35 percent supportive of prerenal physiology
Preferred when diuretics recently used
Targeted labs by differential
Additional labs when indicated
CK
Rhabdomyolysis suspicion
Pigment nephropathy risk
LFTs and INR
Cirrhosis severity
Hepatorenal syndrome context
BNP
Congestive physiology
Volume overload context
Hemolysis panel
LDH
Haptoglobin
Peripheral smear
Autoimmune serologies
ANCA
Anti GBM
Complement levels
Imaging
Scoring Systems
AKI staging and urine output criteria
KDIGO AKI stage
Stage 1
Creatinine 1.5 to 1.9 times baseline or 0.3 mg/dL increase
Urine output < 0.5 mL/kg/hour for 6 to 12 hours
Stage 2
Creatinine 2.0 to 2.9 times baseline
Urine output < 0.5 mL/kg/hour for 12 hours or longer
Stage 3
Creatinine 3.0 times baseline
Creatinine 4.0 mg/dL or higher
Dialysis initiation
Urine output < 0.3 mL/kg/hour for 24 hours or longer
Anuria for 12 hours or longer
Limitations
Creatinine lag in early AKI
Baseline creatinine uncertainty
MRI
MRI applications
Renal artery imaging
MRA when CTA contraindicated
Gadolinium risk in advanced CKD
Renal mass evaluation
Indeterminate lesion characterization
Contrast avoidance considerations
CT
CT pathways
Non contrast CT KUB
Suspected ureteral stone
Hydronephrosis and obstruction evaluation
CT abdomen pelvis with contrast
Alternate abdominal catastrophe concern
Contrast associated AKI risk context
CTA renal arteries when indicated
Suspected renal infarct
Suspected renal artery occlusion
Ultrasound
Ultrasound approaches
Renal ultrasound
Hydronephrosis
Renal size and chronicity clues
Bladder ultrasound
Post void residual
Bladder distension
POCUS integration
IVC assessment limitations
Lung ultrasound for pulmonary edema
Special Tests
Bedside diagnostics and procedures
Bedside tests
Bladder scan
High post void residual supportive of retention
Guides catheterization
Foley catheterization
Immediate urine return supportive of outlet obstruction
Monitor post obstructive diuresis risk
Urine microscopy interpretation
Muddy brown casts supportive of acute tubular injury
RBC casts supportive of glomerulonephritis
Fluid challenge response
Small bolus strategy when not overloaded
Lack of response suggests intrinsic or obstructive etiologies
ECG
Hyperkalemia and uremic complications
ECG priorities
Hyperkalemia patterns
Peaked T waves
PR prolongation
QRS widening
Sine wave risk
Arrhythmias
Bradycardia
Ventricular tachycardia
Uremic pericarditis clues
Diffuse ST elevation possibility
Clinical correlation required
Assessment
Categorize AKI and urgent complications
Working problem list
Oliguria or anuria with suspected AKI (N17.9)
Prerenal
Intrinsic renal
Postrenal
Severity stratification
KDIGO stage based on creatinine and urine output
Rate of rise of creatinine
Immediate complications to rule out
Hyperkalemia
Severe metabolic acidosis
Pulmonary edema
Obstructed infected system
Diagnostic uncertainty flags
Unknown baseline creatinine
Mixed prerenal and intrinsic physiology
Plan
First 5 minutes
Time critical actions
Monitoring and access
Cardiac monitor if K elevation suspected
IV access
Immediate point of care checks
Fingerstick glucose if altered
ECG if K elevation suspected
Rapid obstruction screen
Bladder scan
Foley catheter if retention likely
Severe hyperkalemia treatment if present
Calcium gluconate IV 1 g
Repeat dose if ECG changes persist after 5 to 10 minutes
Insulin regular IV 10 units with dextrose
Dextrose 25 g IV if glucose < 14 mmol/L
Nebulized albuterol 10 to 20 mg
Sodium bicarbonate IV if severe acidosis
Dialysis activation for refractory hyperkalemia
Diagnostic sequencing
Initial diagnostic path
Labs
BMP for K and bicarbonate
Urinalysis with microscopy
Infection evaluation when indicated
Blood cultures
Lactate
Imaging for obstruction
Bedside bladder scan then Foley
Renal ultrasound if anuria or persistent oliguria
Fluids and hemodynamics
Volume and perfusion management
Hypovolemia without overload
Isotonic crystalloid 500 mL bolus
Reassess after each bolus
Heart failure or pulmonary edema
Avoid empiric fluids
Noninvasive ventilation if needed
Shock or sepsis
Local protocol dependent resuscitation volumes
Early vasopressor if fluid nonresponsive
Treat reversible causes
Etiology directed actions
Postrenal
Foley for suspected outlet obstruction
Urology consult for failed catheterization
Nephrostomy consideration for upper tract obstruction
Suspected pyelonephritis with obstruction
Broad spectrum antibiotics
Urgent decompression pathway
Medication related AKI
Stop NSAIDs
Hold ACE inhibitor and ARB during AKI
Review nephrotoxin combinations
Suspected glomerulonephritis
Nephrology consult
Avoid delay in workup when pulmonary hemorrhage concern
Rhabdomyolysis
Isotonic crystalloid infusion
CK trend monitoring
Reassessment loop
Time based reevaluation
Urine output monitoring
Hourly in severe AKI
Foley output measurement
Repeat labs
Potassium recheck within 1 to 2 hours if treated
Creatinine and bicarbonate within 4 to 6 hours if unstable
Fluid balance and respiratory status
Lung findings
Oxygen requirement changes
Post obstructive diuresis monitoring
Urine output > 200 mL/hour for 2 hours
Electrolyte monitoring frequency escalation
Renal replacement therapy triggers
Dialysis indications
Refractory hyperkalemia
Persistent K 6.5 mmol/L or higher
Ongoing ECG changes
Refractory pulmonary edema
Hypoxemia despite therapy
Volume overload not diuretic responsive
Severe metabolic acidosis
pH < 7.1 with clinical deterioration
Refractory to temporizing therapy
Uremic complications
Pericarditis
Encephalopathy
Bleeding with suspected uremic platelet dysfunction
Toxin ingestion
Local protocol dependent dialyzable toxins
Poison control guidance
Disposition
Level of care criteria
ICU or monitored bed
Severe hyperkalemia treated or ongoing risk
ECG changes
K 6.0 mmol/L or higher with AKI
Respiratory failure or pulmonary edema
Noninvasive ventilation
Rising oxygen needs
Shock or sepsis
Vasopressors
Lactate elevation with instability
Dialysis initiation or imminent need
AEIOU indications present
Rapidly rising K or acidosis
Admission and observation
Inpatient admission
New AKI with creatinine rise and ongoing oliguria
KDIGO stage 2 or higher
Unclear etiology
Obstruction requiring intervention
Upper tract obstruction
Failed catheterization
Infection requiring IV therapy
Pyelonephritis
Bacteremia concern
Observation pathway
Prerenal physiology with response to fluids
Improving urine output
Stable electrolytes
Post retention with decompression
Stable electrolytes
No post obstructive diuresis
Discharge criteria
Discharge only if low risk and improving
Clear reversible cause corrected
Mild dehydration with response
Transient retention resolved
Stable labs
Potassium normal range
No severe acidosis
Reliable follow up within 24 to 72 hours
Repeat creatinine arranged
Medication review completed
Discharge Instructions
Copy discharge instructions
Summary
Low urine output related to
Dehydration
Temporary bladder emptying problem
Improvement in emergency department
Urine output improved
Blood tests stable
Medications
Avoid NSAIDs
Ibuprofen
Naproxen
Hold ACE inhibitor or ARB until follow up if instructed
Resume only after repeat labs
Follow clinician guidance
Fluids and diet
Hydration goal unless fluid restriction
Clear urine goal
Stop if shortness of breath worsens
Avoid high potassium foods until cleared if potassium was high
Salt substitutes
Large amounts of juice
Follow up
Repeat blood work
Creatinine
Potassium
Timing
24 to 72 hours
Earlier if symptoms worsen
Return to emergency department now for
No urine output
More than 8 hours
With worsening symptoms
Trouble breathing
New or worse shortness of breath
Chest pain
Infection symptoms
Fever
Rigors
Severe weakness or palpitations
Fainting
Persistent vomiting
Catheter problems if discharged with catheter
No drainage
New severe pain
Large blood clots
References
Guidelines and key sources
Evidence base
KDIGO Clinical Practice Guideline for Acute Kidney Injury, 2012
KDIGO Clinical Practice Guideline for AKI update statements, 2023
Surviving Sepsis Campaign Guidelines, 2021
American Urological Association guidance on acute urinary retention and obstruction, most recent update local protocol dependent
National Kidney Foundation guidance on hyperkalemia management, recent consensus statements local protocol dependent
SymptomDx is an educational tool for medical professionals. It does not replace clinical judgment. Verify all clinical data and drug dosages with authoritative sources.