Understanding Your Kidneys

Your kidneys are two bean-shaped organs that quietly work around the clock to support many important functions in the body.

They help filter waste from the blood, regulate fluid and electrolyte balance, contribute to blood pressure regulation, and support red blood cell production.

Kidney problems can sometimes develop gradually, and early changes may not always cause noticeable symptoms. Knowing some possible warning signs can help you recognize when it may be worth discussing your health with a medical professional.

Here are 23 signs that may be associated with kidney problems. Keep in mind that these symptoms can have many different causes and do not automatically mean that you have kidney disease.

1. Ongoing Fatigue

The kidneys produce a hormone called erythropoietin, which helps the body make red blood cells.

When kidney function becomes impaired, production of this hormone may decrease, potentially contributing to anemia. This can be associated with tiredness, weakness, or reduced energy.

However, fatigue is common and may have many possible causes, so persistent tiredness deserves appropriate evaluation.

2. Trouble Sleeping

Changes in kidney function can sometimes be associated with sleep difficulties.

When the kidneys are not filtering waste efficiently, certain substances may accumulate in the body. Kidney disease can also occur alongside sleep-related conditions.

Still, occasional difficulty sleeping is common and does not by itself indicate a kidney problem.

3. Dry or Itchy Skin

Healthy kidneys help maintain an appropriate balance of minerals and other substances in the blood.

When kidney function declines, changes in mineral balance may contribute to dry, flaky, or itchy skin, particularly in more advanced kidney disease.

There are many other possible causes of itching, including allergies, skin conditions, and environmental factors.

4. Frequent Urination at Night

Waking several times during the night to urinate is known as nocturia.

It can sometimes occur with kidney problems, but it may also be related to urinary tract conditions, diabetes, prostate enlargement, certain medications, or drinking large amounts of fluid in the evening.

If nighttime urination becomes noticeably more frequent or persistent, consider discussing it with a healthcare professional.

5. Persistent Foamy Urine

Occasional bubbles or foam in urine can happen simply because of the force of the urine stream.

However, persistent, unusually foamy urine may sometimes indicate excess protein in the urine, known as proteinuria.

Protein in the urine can be an important finding because it may indicate that the kidney’s filtering system needs further evaluation.

6. Swelling in the Feet, Ankles, or Hands

The kidneys help remove excess sodium and fluid from the body.

When fluid balance is affected, swelling, also called edema, may develop around the feet, ankles, legs, or hands.

Swelling can also have other causes, including heart, liver, vein, or medication-related conditions.

7. Puffiness Around the Eyes

Puffiness around the eyes, especially in the morning, can sometimes be associated with protein loss through the urine.

When significant amounts of protein are lost, fluid may move more easily into surrounding tissues.

However, morning puffiness can also be related to lack of sleep, allergies, or a high-sodium diet.

8. High Blood Pressure

The kidneys play an important role in maintaining healthy blood pressure.

Kidney problems may make blood pressure more difficult to control, while long-term uncontrolled high blood pressure can also damage the small blood vessels within the kidneys.

This means kidney health and blood pressure are closely connected.

9. Shortness of Breath

Kidney problems can sometimes contribute to shortness of breath.

One possible reason is excess fluid accumulation, while anemia associated with reduced kidney function may also affect how much oxygen reaches body tissues.

Sudden or severe shortness of breath, especially when accompanied by chest pain, requires prompt medical attention.

10. A Metallic or Unusual Taste

Changes in taste can sometimes occur when waste products build up in the blood in advanced kidney disease.

Some people describe food as tasting metallic, bitter, or simply different than usual.

Changes in taste can also result from medications, infections, dental problems, or other conditions.

11. Reduced Appetite

Changes in appetite may occur alongside nausea, taste changes, or the accumulation of waste products associated with reduced kidney function.

However, appetite loss is not specific to kidney disease.

Persistent appetite changes, particularly when accompanied by unexplained weight loss, should be discussed with a healthcare professional.

12. Muscle Cramps

The kidneys help regulate minerals and electrolytes such as calcium, potassium, and sodium.

Changes in these levels may sometimes contribute to muscle cramps or discomfort.

Dehydration, physical activity, medications, and several other conditions can also cause cramps.

13. Difficulty Concentrating

Anemia can reduce the amount of oxygen delivered to the body’s tissues and may contribute to tiredness or difficulty concentrating.

In more advanced kidney disease, the buildup of waste products may also affect mental clarity.

Sudden confusion or significant changes in awareness should always be assessed promptly.

14. Feeling Cold More Often

People with anemia may feel unusually cold even when the surrounding temperature is comfortable.

Because reduced kidney function can contribute to anemia, increased sensitivity to cold may sometimes occur alongside kidney disease.

Other possibilities include thyroid problems, circulation issues, or low body weight.

15. Pain in the Back or Side

The kidneys are located toward the back of the abdomen, on either side of the spine.

Pain in the side or back may sometimes occur with conditions such as kidney stones or kidney infections.

At the same time, most lower-back pain is related to muscles, joints, or the spine rather than the kidneys.

Severe pain accompanied by fever, nausea, vomiting, or blood in the urine should be evaluated promptly.

16. Changes in Skin Appearance

In advanced kidney disease, changes in waste levels and anemia may sometimes affect the appearance of the skin.

The skin may appear paler or somewhat grayish or yellowish.

Because changes in skin color have many possible causes, they should not automatically be attributed to kidney disease.

17. Persistent Itching

Kidney-related itching may occur without an obvious skin rash.

It can sometimes become persistent and affect areas such as the back, arms, or legs, particularly in advanced kidney disease.

Other skin and systemic conditions can cause similar symptoms, so proper evaluation is important.

18. Unexplained Weight Loss

Unexpected weight loss can have many possible explanations.

In people with significant kidney problems, reduced appetite, nausea, vomiting, or changes in taste may contribute to weight loss.

Any ongoing or unexplained weight change is worth discussing with a healthcare professional.

19. Nausea or Vomiting

When kidney function becomes significantly reduced, waste products may accumulate in the blood.

This can sometimes contribute to nausea, vomiting, or persistent stomach discomfort.

Because these symptoms are common with many illnesses, they should be considered alongside other symptoms and medical findings.

20. Unusual Breath Odor

Advanced kidney dysfunction can sometimes be associated with an unusual breath odor caused by increased levels of urea in the blood.

However, bad breath is much more commonly associated with dental problems, dry mouth, certain foods, or other health conditions.

Persistent changes in breath odor should be evaluated rather than automatically linked to the kidneys.

21. Noticeably Reduced Urine Output

A significant decrease in urine production can sometimes occur when kidney function is severely affected.

Sudden changes may also be related to dehydration, urinary obstruction, certain medications, or acute kidney injury.

A major or sudden reduction in urine output should receive prompt medical assessment.

22. Dark, Pink, Red, or Brown Urine

Urine that appears pink, red, brown, or tea-colored may contain blood, a condition known as hematuria.

Blood in the urine can have several causes, including urinary tract infections, kidney stones, kidney conditions, prostate problems, and other urinary tract disorders.

Visible blood in the urine should be discussed with a healthcare professional, even if there is no pain.

23. Abdominal Swelling

Significant fluid retention can sometimes contribute to abdominal swelling.

However, abdominal bloating or enlargement can also result from digestive conditions, liver problems, heart conditions, or many other causes.

Persistent abdominal swelling, particularly when accompanied by breathing difficulties, deserves medical evaluation.

Simple Ways to Support Kidney Health

Having one or more of these symptoms does not necessarily mean that you have kidney disease. Many of them are common and can occur for completely different reasons.

Still, healthy daily habits can support overall kidney and cardiovascular health.

Stay Adequately Hydrated

Drink fluids regularly according to your thirst, activity level, climate, and individual health needs.

More water is not always better. People with certain kidney or heart conditions may need specific fluid recommendations from their healthcare professional.

Be Mindful of Salt

A high-sodium diet can contribute to fluid retention and elevated blood pressure.

Try to limit heavily processed foods, salty snacks, processed meats, and foods with large amounts of added sodium.

Choose a Balanced Diet

A balanced eating pattern can include vegetables, fruits, whole grains, legumes, and appropriate sources of protein.

If you already have kidney disease, your nutritional needs may be different. Protein, potassium, phosphorus, and fluid recommendations should be individualized with guidance from a healthcare professional.

Keep Blood Pressure in a Healthy Range

Long-term high blood pressure can gradually damage the kidneys.

If you are at increased risk, regular blood pressure checks and following your prescribed treatment plan can be important parts of kidney care.

Manage Blood Sugar

Diabetes is a major risk factor for chronic kidney disease.

Keeping blood sugar within the range recommended by your healthcare professional can help reduce the risk of damage to blood vessels and other organs.

Be Careful With Certain Pain Relievers

Nonsteroidal anti-inflammatory drugs, including ibuprofen and naproxen, can affect kidney function in some people, especially when used frequently, at high doses, or in people with certain health conditions.

If you need these medicines regularly, ask a doctor or pharmacist whether they are appropriate for you.

Avoid Smoking

Smoking can damage blood vessels and affect circulation throughout the body.

Quitting smoking can support overall cardiovascular and kidney health.

Stay Physically Active

Regular physical activity can help support healthy blood pressure, blood sugar, and body weight.

You do not necessarily need intense workouts. Walking and other moderate activities can be useful ways to stay active.

Consider Routine Health Checks

People with a higher risk of kidney disease may benefit from discussing regular screening with a healthcare professional.

Depending on individual circumstances, testing may include:

• Blood pressure measurement
• Blood creatinine testing
• Estimated glomerular filtration rate (eGFR)
• Urine testing for protein or albumin

Important risk factors can include diabetes, high blood pressure, cardiovascular disease, obesity, and a family history of kidney disease.

When Should You Talk With a Healthcare Professional?

Kidney symptoms can be subtle, and some people with chronic kidney disease may have few noticeable symptoms in the early stages.

Consider seeking medical advice if you experience persistent or unexplained changes such as:

• Blood in the urine
• A significant decrease in urine output
• Persistent swelling
• Ongoing foamy urine
• Unexplained weight loss
• Persistent nausea or vomiting
• Severe or unusual side or back pain
• Shortness of breath
• Significant or persistent fatigue

Sudden severe symptoms, such as difficulty breathing, confusion, severe pain, or a major decrease in urine output, should be assessed promptly.

Final Thoughts

Your kidneys perform essential work every day, often without drawing much attention.

The 23 signs discussed above are not a diagnosis. Many can occur because of conditions unrelated to the kidneys. However, persistent or unusual changes can be a useful reason to check in with a healthcare professional.

Simple habits such as managing blood pressure and blood sugar, limiting excess sodium, staying appropriately active, avoiding smoking, and taking medicines responsibly can all contribute to better overall health.

If you have risk factors for kidney disease, routine blood and urine testing can provide valuable information even before noticeable symptoms appear.

Health Disclaimer: This article is intended for general educational purposes only. It does not diagnose, treat, or prevent any medical condition and should not replace personalized advice from a qualified healthcare professional.