Your kidneys are two bean-shaped organs located just below your rib cage, one on each side of your spine. They may be small, but their role in your overall health is enormous. Every day, they filter around 120 to 150 quarts of blood to remove waste and excess fluids, producing about 1 to 2 quarts of urine. They also help regulate blood pressure, produce red blood cells, and maintain the right balance of minerals like sodium, potassium, and phosphorus in your body.
When your kidneys are damaged, waste builds up in your blood, leading to serious health complications. Unfortunately, kidney disease often progresses silently, with many people unaware of the problem until significant damage has already occurred. Recognizing the early warning signs can help you take action before it’s too late.
Here are 12 alarming signs that your kidneys may be in danger. If you experience any of these symptoms, especially if they persist, consult a doctor for proper evaluation.
1. Fatigue and Weakness
One of the earliest and most common signs of kidney trouble is an overwhelming sense of fatigue. Healthy kidneys produce a hormone called erythropoietin (EPO), which signals your bone marrow to make red blood cells. These cells carry oxygen throughout your body. When kidney function declines, EPO production drops, leading to fewer red blood cells—a condition known as anemia.
With anemia, your muscles and brain tire quickly because they aren’t getting enough oxygen. You may feel exhausted even after a full night’s sleep, struggle with concentration, or feel unusually weak during routine activities. Many people dismiss this fatigue as stress or lack of sleep, but if it persists, it could be a sign of kidney dysfunction.
2. Swelling in Hands, Feet, or Face (Edema)
Your kidneys regulate fluid balance by removing excess water and sodium. When they aren’t working properly, fluid builds up in your tissues, causing swelling (edema). This is most noticeable in the hands, feet, ankles, and face, particularly around the eyes.
Puffiness in the morning that doesn’t go away could indicate that your kidneys are struggling. In severe cases, swelling can extend to the legs and abdomen. If pressing your finger into swollen skin leaves a dent that takes time to disappear, this is called pitting edema and should be checked by a doctor.
3. Changes in Urination
Since your kidneys produce urine, any unusual changes in urination habits can signal a problem. Some key warning signs include:
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Frequent urination, especially at night – Waking up multiple times to urinate (nocturia) can indicate kidney disease or an enlarged prostate in men.
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Foamy or bubbly urine – Excessive protein in the urine (proteinuria) makes it frothy, similar to how soap bubbles look.
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Dark, bloody, or cloudy urine – Blood in the urine (hematuria) can be caused by kidney stones, infections, or even tumors.
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Pain or burning during urination – This may suggest a urinary tract infection (UTI) or kidney stones.
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Reduced urine output – Producing very little urine despite drinking enough fluids is a serious warning sign.
4. Persistent Itching and Dry Skin
When kidneys fail to filter waste properly, toxins accumulate in the bloodstream, leading to a condition called uremia. This can cause severe itching, often deep under the skin, and dryness that lotions can’t relieve.
Additionally, kidney disease disrupts the balance of calcium and phosphorus in your body, leading to mineral deposits in the skin that worsen itching. If you notice persistent itching without a rash, especially if accompanied by other symptoms, your kidneys may be struggling.
5. Metallic Taste in the Mouth or Bad Breath
A buildup of waste products in the blood (uremia) can cause a metallic or ammonia-like taste in your mouth. Some people describe it as tasting like they’ve been sucking on pennies. You may also develop bad breath that smells like urine or ammonia.
This happens because toxins that should be filtered out by the kidneys remain in your bloodstream, affecting your sense of taste and smell. Many people with kidney disease also lose their appetite, especially for meat, because food tastes different.
6. Nausea and Vomiting
Severe kidney dysfunction leads to a buildup of waste products in the blood, which can trigger nausea and vomiting. Many people mistake these symptoms for stomach flu or food poisoning, but if they persist without another obvious cause, kidney disease could be the culprit.
In advanced stages, vomiting may become frequent, leading to dehydration and weight loss. If nausea is accompanied by other kidney-related symptoms (like swelling or changes in urination), see a doctor immediately.
7. Shortness of Breath
Kidney disease can cause shortness of breath in two ways:
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Fluid buildup in the lungs – When kidneys fail, excess fluid can accumulate in the lungs, making it hard to breathe.
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Anemia – Low red blood cell count means less oxygen is delivered to your body, leaving you breathless even with mild activity.
Some people with kidney disease wake up gasping for air or feel like they can’t take a deep breath. If you experience unexplained shortness of breath, especially when lying down, it could be related to kidney or heart problems.
8. High Blood Pressure
Your kidneys and blood pressure are closely linked. Kidneys help regulate blood pressure by controlling fluid balance and releasing hormones. When they are damaged, blood pressure can rise dangerously.
At the same time, uncontrolled high blood pressure damages the tiny blood vessels in the kidneys, worsening kidney function. This creates a vicious cycle where high blood pressure leads to kidney damage, and kidney damage leads to higher blood pressure.
If your blood pressure is consistently high despite medication, your doctor should check your kidney function.
9. Back or Side Pain
While most early kidney disease doesn’t cause pain, certain conditions can lead to discomfort in the back or side, just below the ribs. Possible causes include:
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Kidney infections – These often cause sharp pain, fever, and nausea.
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Kidney stones – Severe, cramping pain that comes in waves as the stone moves.
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Polycystic kidney disease (PKD) – A genetic disorder where cysts grow on the kidneys, causing dull, persistent pain.
If you have unexplained back pain along with other kidney-related symptoms, get medical attention.
10. Muscle Cramps and Twitching
Electrolyte imbalances due to kidney dysfunction can cause muscle cramps, twitching, or weakness. Low calcium, high phosphorus, or high potassium levels are common in kidney disease and can affect nerve and muscle function.
Painful leg cramps, especially at night, are a frequent complaint. If you notice frequent muscle spasms without exercise or dehydration as a cause, your kidneys may be involved.
11. Feeling Cold All the Time
Anemia from kidney disease reduces oxygen flow to your tissues, making you feel unusually cold, even in warm environments. You may also experience chills, dizziness, or pale skin.
If you’re always reaching for a sweater while others are comfortable, and you have other symptoms like fatigue, it’s worth checking your kidney function.
12. Trouble Sleeping
Toxins that build up in the blood when kidneys fail can interfere with sleep. Many people with kidney disease experience:
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Insomnia – Difficulty falling or staying asleep.
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Restless legs syndrome (RLS) – An uncontrollable urge to move the legs, especially at night.
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Sleep apnea – A condition where breathing repeatedly stops and starts during sleep.
Poor sleep worsens fatigue and overall health, so if you’re struggling with sleep along with other symptoms, kidney function tests may be needed.
What Should You Do If You Notice These Signs?
If you recognize any of these symptoms, don’t ignore them. Early detection can slow or even prevent further kidney damage. Here’s what you can do:
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Get tested – A simple blood test (creatinine, GFR) and urine test (protein, blood) can assess kidney function.
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Monitor blood pressure – Keep it under 120/80 mmHg to protect your kidneys.
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Stay hydrated – Drink enough water, but avoid excessive fluid if you have advanced kidney disease.
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Eat a kidney-friendly diet – Reduce salt, processed foods, and excessive protein.
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Avoid NSAIDs – Painkillers like ibuprofen can harm kidneys if overused.
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Control diabetes and hypertension – These are the leading causes of kidney disease.
Final Thoughts
Kidney disease often develops silently, but your body gives warning signs. Fatigue, swelling, changes in urination, and persistent itching are just a few red flags. If you’re at risk (due to diabetes, high blood pressure, or family history), regular check-ups are crucial.
Your kidneys are essential for survival—take care of them before it’s too late. If you notice any of these symptoms, see a doctor promptly. Early action can make all the difference in preserving your kidney health and overall well-being.