AKI can be diagnosed if any one of the following is present:

Increase in SCr by ≥0.3 mg/dl (≥26.5 μmol/L) within 48 hours; or
Increase in SCr to ≥1.5 times baseline, which has occurred within the prior 7 days; or
Urine volume < 0.5 mL/kg/h for 6 hours. Staging
The RIFLE criteria, proposed by the Acute Dialysis Quality Initiative (ADQI) group, aid in assessment of the severity of a persons acute kidney injury. The acronym RIFLE is used to define the spectrum of progressive kidney injury seen in AKI:

Risk: 1.5-fold increase in the serum creatinine, or glomerular filtration rate (GFR) decrease by 25 percent, or urine output <0.5 mL/kg per hour for six hours. Injury: Two-fold increase in the serum creatinine, or GFR decrease by 50 percent, or urine output <0.5 mL/kg per hour for 12 hours. Failure: Three-fold increase in the serum creatinine, or GFR decrease by 75 percent, or urine output of <0.3 mL/kg per hour for 24 hours, or no urine output (anuria) for 12 hours. Loss: Complete loss of kidney function (e.g., need for renal replacement therapy) for more than four weeks. End-stage kidney disease: Complete loss of kidney function (e.g., need for renal replacement therapy) for more than three months. Evaluation
The deterioration of kidney function may be signaled by a measurable decrease in urine output. Often, it is diagnosed on the basis of blood tests for substances normally eliminated by the kidney: urea and creatinine. Additionally, the ratio of BUN to creatinine is used to evaluate kidney injury. Both tests have their disadvantages.
Pili annulati (also known as "ringed hair") is a genetic trait in which the hair seems ‘banded‘ by alternating segments of light and dark color when seen in reflected light. : 767 : 640

See also
Pili pseudoannulati
List of cutaneous conditions

References
External links
Hair Transplant