Don’t wait until dialysis to feel regret: 5 kid.ney “SOS signals” that 90% of patients ignore

Chronic kidney disease is often called a “silent killer” because it progresses quietly. Many people only seek medical care when they develop facial swelling, leg edema, or shortness of breath while walking—only to be shocked to learn their kidneys are already failing.

Recently, a retired teacher was hospitalized with facial swelling, breathlessness, and frequent nighttime urination. His family was stunned when doctors diagnosed kidney failure, even though he had no history of high blood pressure or serious underlying disease.

In reality, the kidneys are the body’s most “silent” organs. They work tirelessly, filtering about 150 liters of blood each day to remove toxins. By the time symptoms become obvious, the disease is often already advanced.

A recent analysis by Peking Union Medical College Hospital of 417 kidney failure patients identified common “red flags” that most people tend to overlook. If you notice any of the five signs below, be alert—your kidneys may be in danger.

Five warning signs of kidney failure to watch for

1. Swelling (edema): Don’t blame salt or drinking too much water
Many people notice puffy eyes in the morning or mild ankle swelling and assume it’s due to salty food or excess fluids. A classic kidney-related sign is “pitting edema”: when you press on swollen skin (such as the ankle or shin), the indentation takes several seconds to rebound.
When kidney function declines, excess fluid cannot be excreted and accumulates in tissues. Over 80% of patients in the study showed this sign early on.

2. Sudden increase in nighttime urination: the kidneys are overloaded
Normally, urine output decreases during sleep. If you wake up to urinate more than twice a night—and in significant amounts—this may indicate impaired tubular reabsorption. Don’t dismiss it as “just aging”; it is one of the earliest indicators of kidney dysfunction.

3. Abnormal blood pressure fluctuations
Kidneys and blood pressure are closely linked. Declining kidney function disrupts hormone systems that regulate blood pressure, often leading to hypertension. In turn, long-term high blood pressure damages the kidney’s filtering units, creating a vicious cycle.
According to data from PUMCH, over 90% of kidney failure patients had hypertension or unstable blood pressure before diagnosis.

4. Anemia: unexplained fatigue
Dizziness, weakness, or shortness of breath after minimal activity—especially in women—is often blamed on iron deficiency. Few people realize the kidneys produce erythropoietin (EPO), a hormone that stimulates red blood cell production.
When kidneys fail, red blood cell levels drop, causing chronic anemia that cannot be corrected by supplements alone and requires addressing kidney function.

5. Foamy urine (proteinuria)
This painless but easily missed sign occurs when damaged kidney filters allow protein to leak into urine, forming persistent foam.
If your urine looks soapy and the bubbles linger, get a urine test immediately. This is one of the earliest markers of kidney damage.

Don’t ignore small warning signs

The kidneys are like diligent sanitation workers—they only “go on strike” when completely exhausted. In modern life, high-salt diets, staying up late, lack of exercise, and especially the uncontrolled use of painkillers or supplements quietly erode kidney health.

Expert advice

• Don’t be complacent: Swelling and frequent nighttime urination are not trivial issues.

• Get regular screening: Urinalysis and kidney function tests are essential, especially for people with diabetes or high blood pressure.

• Adopt a kidney-friendly lifestyle: Reduce salt, drink adequate (not excessive) water, and never take unverified medications or supplements on your own.

Early detection of kidney disease can stabilize the condition and, in some cases, even reverse damage. Don’t wait until life depends on dialysis to say “if only.”

This content is for reference only. If you experience the symptoms above, please visit a medical facility for professional evaluation.