What Is Chronic Kidney Disease?

Chronic kidney disease (CKD) is a slow, often silent loss of kidney function that affects more than 1 in 7 adults in the United States — yet up to 9 in 10 of them don't know they have it. This explainer covers what causes CKD, how doctors detect and stage it, what standard treatment looks like today, and where stem cell and cell-therapy research for CKD actually stands: mostly early-phase human safety trials, with one small but genuinely interesting signal worth watching, not a proven or approved treatment.

Causes and Risk Factors

CKD means the kidneys have been damaged over months or years and can no longer filter waste and excess fluid from the blood as well as they should. The two leading causes are diabetes and high blood pressure. High blood glucose gradually damages the kidneys' tiny filtering units, while high blood pressure injures the blood vessels and filtering structures inside the kidneys — and declining kidney function can, in turn, push blood pressure even higher, creating a damaging cycle. According to the CDC, roughly 1 in 3 adults with diabetes and roughly 1 in 5 adults with high blood pressure has some degree of CKD.

Other causes include glomerular diseases (such as IgA nephropathy and focal segmental glomerulosclerosis), polycystic kidney disease, autoimmune disorders like lupus, repeated kidney infections or kidney stones with complications, heart disease, severe obesity, certain cancers, kidney-toxic medications, and genetic conditions such as Alport syndrome or sickle cell disease. Risk rises sharply with age — about 1 in 3 adults 65 and older has CKD, compared with roughly 1 in 16 adults under 45 — and a family history of kidney failure also raises risk. Prevalence is notably higher among Black adults (about 1 in 5) than White adults (about 1 in 8).

Symptoms

This is the part that catches many people off guard: early CKD usually causes no symptoms at all. Kidneys have a lot of reserve capacity, so function can decline substantially before anything feels wrong — which is exactly why the disease is so often diagnosed late, if it's diagnosed at all. As damage progresses, people may notice fatigue, swelling in the legs, ankles, or around the eyes, changes in how often or how much they urinate (including foamy or dark urine), loss of appetite, nausea, muscle cramps, itchy skin, trouble concentrating, and difficulty keeping blood pressure under control. By the time these symptoms are obvious, significant kidney function has often already been lost.

Standard Care Today

CKD is diagnosed and staged mainly through two blood and urine measures: estimated glomerular filtration rate (eGFR), which approximates how well the kidneys are filtering, and urine albumin, which flags leakage of protein that shouldn't be there. An eGFR of 60 or above is generally in the normal range; below 60 may signal kidney disease; and an eGFR of 15 or lower is kidney failure, at which point most people need dialysis or a transplant to survive. Doctors use these numbers, tracked over time, to sort CKD into stages from mild to severe.

There is no cure for CKD, so treatment focuses on slowing its progression and managing complications. That means tightly controlling blood sugar and blood pressure; using medications such as ACE inhibitors or ARBs, which both lower blood pressure and specifically protect kidney filtering units; and, more recently, SGLT2 inhibitors, a newer drug class now used in many CKD patients regardless of diabetes status because large trials have shown they can slow functional decline. Dietary adjustments (sodium, protein, and sometimes potassium or phosphorus limits), avoiding kidney-toxic drugs like regular NSAID use, and treating the underlying cause round out typical care. When kidney function falls to the point of failure, the remaining options are dialysis or kidney transplantation — both of which manage the disease rather than reverse it.

Where Stem Cell / Cell Therapy Research Stands

Regenerative approaches to CKD are still early. Laboratory and animal research suggests mesenchymal stem/stromal cells (MSCs) may help by calming inflammation, reducing cell death in kidney tubules, limiting scarring (fibrosis), and supporting blood vessel repair — mostly through the signaling molecules they release rather than by rebuilding kidney tissue directly. Translating that into a human treatment is a different matter.

The most informative human data so far comes from NEPHSTROM, a small phase 1b/2a trial that gave a single infusion of an MSC product (ORBCEL-M) to patients with type 2 diabetes and kidney disease. In a cohort of just 16 men, the cell-treated group showed a notably slower annual decline in eGFR than the placebo group — an encouraging, statistically significant result in such a small study. But the trial's own investigators were careful to frame it as preliminary: it wasn't designed or powered to prove effectiveness, one participant developed low-level immune sensitization, and the authors explicitly called for larger, longer trials before drawing conclusions. A handful of other early-phase safety trials of MSCs in CKD are now registered and recruiting, but none has produced results robust enough to change clinical practice, and no stem cell or cell therapy is FDA-approved for CKD.

Bottom Line

Chronic kidney disease is common, frequently silent in its early stages, and driven overwhelmingly by diabetes and high blood pressure — which also makes it one of the more preventable forms of organ damage when those conditions are well controlled. Standard care today (blood pressure and glucose control, protective medications, and dialysis or transplant for kidney failure) remains the proven path. Stem cell research for CKD is real and mechanistically plausible, with one small trial hinting that MSC infusions might slow eGFR decline — but this is early-phase, unproven science, not an available treatment. Anyone exploring it should treat it as investigational and be wary of any clinic claiming otherwise.