Chronic Kidney Disease (CKD)
CKD is the gradual loss of kidney function over months or years. The most common causes are diabetes and high blood pressure, which together account for over two-thirds of all CKD. Early CKD usually has no symptoms; it is detected through blood tests (eGFR) and urine tests (urine albumin). CKD is divided into five stages based on how well the kidneys filter, with Stage 5 representing kidney failure that requires dialysis or transplantation. About 1 in 7 US adults has CKD, and most do not know it.
Acute Kidney Injury (AKI)
AKI is sudden kidney function loss — over hours to days — from a clear cause: severe dehydration, infection, medication injury, contrast dye, or obstruction. Unlike CKD, AKI is often reversible if the underlying cause is treated quickly. AKI most commonly happens during hospitalization. Even when AKI resolves, the kidneys may not return fully to baseline, which is why prevention and prompt treatment matter.
Kidney Stones
Kidney stones are crystallized deposits that form in the urinary tract, most commonly from calcium oxalate. They cause severe flank pain that radiates to the groin and is often described as worse than childbirth. Most stones pass on their own with hydration and pain control, though larger stones may require lithotripsy or surgical removal. Recurrent stones can be reduced through dietary changes, increased fluid intake, and sometimes medication.
Glomerulonephritis
Glomerulonephritis is inflammation of the glomeruli — the tiny filters in the kidneys. It can be acute or chronic, and causes range from autoimmune diseases (lupus, IgA nephropathy) to infection-related triggers. Symptoms may include blood in the urine, foamy urine, swelling, and high blood pressure. Diagnosis often requires a kidney biopsy, and treatment depends on the specific cause but may include immunosuppressive medications.
Polycystic Kidney Disease (PKD)
PKD is an inherited disease in which fluid-filled cysts develop in the kidneys, eventually replacing healthy tissue. Most patients are diagnosed in adulthood, often after a parent or sibling is diagnosed. PKD progresses gradually and may eventually require dialysis or transplantation. New medications can slow progression in some patients.
Other kidney conditions
Less common but important conditions include diabetic nephropathy (a specific kidney complication of diabetes), hypertensive nephrosclerosis (kidney damage from chronic high blood pressure), interstitial nephritis (inflammation often from medications), and renal artery stenosis (narrowing of the artery to the kidney). Each has distinct causes, diagnostic patterns, and treatments — nephrology evaluation is essential to identify and manage them appropriately.