Recognizing the Symptoms of Kidney Failure: Warning Signs, Causes, and What to Do
Understand the key symptoms, causes, and complications of kidney failure and learn when to seek urgent medical care.
Kidney failure, also known as renal failure, is a condition in which the kidneys lose their ability to filter waste and excess fluids from the blood, resulting in a buildup of toxins and potentially life-threatening complications. Kidney failure can develop suddenly (acute kidney injury) or progress gradually over years (chronic kidney disease). Understanding the warning signs and symptoms of kidney failure is crucial for timely diagnosis and intervention.
What Is Kidney Failure?
Kidney failure occurs when the kidneys are no longer able to effectively filter waste and maintain fluid and electrolyte balance in the body. This failure impairs crucial processes such as blood filtration, toxin removal, and fluid regulation. Kidney failure can progress from chronic kidney disease (CKD) or develop rapidly in cases of acute kidney injury (AKI). Without intervention, kidney failure can quickly become life-threatening.
Key Symptoms of Kidney Failure
Symptoms might appear gradually (as in CKD) or suddenly (as in AKI). Early stages of kidney disease may have few or no obvious symptoms, but as the condition advances, the signs become more prominent and potentially severe.
- Urinary problems
- Swelling (Edema)
- Shortness of breath
- Fatigue
- Gastrointestinal issues
- Neurological symptoms
- Muscle cramps
Urinary Problems
The kidneys contain around one million nephrons, each holding a filtering unit known as a glomerulus. The glomeruli filter toxins, acids, and excess fluids from the blood, producing urine. When the nephrons and glomeruli become damaged due to CKD or AKI, the ability to filter is compromised, leading to noticeable urinary changes:
- Increased urge to urinate, especially at night (nocturia)
- Reduced urine output (oliguria) or no urine output (anuria), especially as kidney failure progresses
- Dark-colored urine
- Blood in the urine (hematuria)
- Foamy or bubbly urine indicating proteinuria
These changes can indicate severe kidney impairment and should prompt immediate medical evaluation.
Edema (Swelling)
One of the most common symptoms of kidney failure is swelling, medically referred to as edema. When the kidneys cannot remove excess fluid and sodium from the body, fluid builds up in tissues. Swelling may affect:
- Feet, ankles, and legs (peripheral edema)
- Arms and hands
- Area around the eyes (periorbital edema)
- Abdomen (ascites)
Severe fluid retention can lead to pulmonary edema, where fluid accumulates in the lungs, making breathing increasingly difficult.
Shortness of Breath
When fluid overload from kidney failure travels to the lungs, it causes pulmonary edema. This leads to shortness of breath (dyspnea), which may be sudden and severe. Individuals with underlying heart problems are at a higher risk of developing this symptom, as heart and kidney disease often coexist and exacerbate each other’s impact on fluid regulation.
What others are reading
Fatigue
Fatigue is a hallmark of advanced kidney disease. While common in early stages, it typically becomes more pronounced as kidney failure approaches. The exact mechanism isn’t fully understood but is thought to be due to:
- Toxin buildup in the bloodstream
- Decreased production of erythropoietin, a hormone that stimulates red blood cell production, resulting in anemia
- Loss of appetite and poor nutritional intake
This fatigue is persistent, not easily relieved by rest, and often accompanied by weakness and lack of energy.
Gastrointestinal Symptoms
When kidney failure impairs waste removal, high levels of urea and other toxins enter the digestive system. This can produce several unpleasant symptoms:
- Nausea
- Vomiting
- Loss of appetite
- Metallic taste in the mouth
- Unintentional weight loss
Sustained nausea and vomiting may indicate severe toxin buildup and require urgent medical attention.
Neurological Symptoms
High levels of waste products can affect the nervous system, leading to:
- Confusion and trouble concentrating
- Headaches
- Trouble sleeping (insomnia)
- Restless legs syndrome
- Seizures (in advanced cases)
- Numbness or tingling in fingers or toes (peripheral neuropathy)
Muscle Cramps and Other Signs
Loss of kidney function disrupts electrolyte levels, causing imbalances that can produce muscle cramps and twitching. Other notable symptoms may include:
- Itchy skin (pruritus)
- Paleness (due to anemia)
- Bruising and bleeding more easily
Acute vs. Chronic Kidney Failure: Differences in Symptom Progression
| Acute Kidney Injury (AKI) | Chronic Kidney Disease (CKD) / Chronic Kidney Failure |
|---|---|
| Symptoms develop quickly (hours to days) | Symptoms develop over months or years |
| Commonly triggered by infections, injury, toxins, or severe dehydration | Commonly caused by diabetes, hypertension, prolonged kidney disease |
| Often reversible if treated promptly | Progressive and usually irreversible, but progression can be slowed |
| Decreased or no urine output is typical | Early increased urination, then reduced output as failure progresses |
Complications of Untreated Kidney Failure
Without appropriate treatment or management, kidney failure can rapidly escalate into life-threatening conditions, including:
- Pulmonary edema (fluid in the lungs)
- Severe electrolyte imbalances (such as life-threatening potassium abnormalities)
- Heart rhythm abnormalities (arrhythmias)
- High blood pressure (hypertension)
- Seizures, confusion, or coma
- Heart failure
- Systemic infections (sepsis)
When to Seek Immediate Medical Care
- Sudden reduction in urine output
- Swelling accompanied by difficulty breathing
- Confusion, seizures, or loss of consciousness
- Severe nausea or vomiting that prevents you from keeping fluids down
- Blood in the urine or black, tar-like stools
If you experience any of these symptoms, seek urgent medical attention. Immediate treatment may stabilize the condition and prevent fatal complications.
Common Causes of Kidney Failure
Causes of Acute Kidney Injury (AKI)
- Severe infections or sepsis
- Dehydration or blood loss
- Blockage in the urinary tract (due to kidney stones, tumors, or enlarged prostate)
- Medications (such as NSAIDs, certain antibiotics, diuretics, or contrast agents)
- Inflammation of the kidney’s blood vessels (vasculitis)
- Heart failure or reduced blood flow to the kidneys
Common Causes of Chronic Kidney Disease (CKD) and Kidney Failure
- Diabetes (most common cause globally)
- High blood pressure (hypertension)
- Chronic glomerulonephritis or other inflammatory kidney diseases
- Hereditary conditions, like polycystic kidney disease
Risk Factors for Developing Kidney Failure
- Family history of kidney disease
- History of diabetes or uncontrolled blood pressure
- Cardiovascular disease
- Older age
- Frequent use of medications that can harm the kidneys (e.g., NSAIDs)
Diagnosis of Kidney Failure
Health professionals use a combination of tests to assess kidney function and confirm kidney failure:
- Blood Tests: Measure creatinine, urea, and estimate the glomerular filtration rate (eGFR)
- Urine Tests: Check for the presence of protein (albuminuria), blood, or abnormal cellular elements
- Imaging: Ultrasound, CT, or MRI to visualize the kidneys and urinary tract for obstructions or structural changes
Managing and Treating Kidney Failure
Timely diagnosis and management are key to minimizing complications. Treatment options vary depending on the stage and type of kidney failure:
- Acute Kidney Injury: Often reversible with prompt medical intervention, such as fluid management, stopping causative drugs, treating infections, and relieving obstructions
- Chronic Kidney Failure: Management includes controlling blood pressure and blood sugar, dietary modifications, medications to treat complications (anemia, bone disease), and treating underlying causes
- Dialysis: Required when kidney function drops severely, to filter blood externally
- Kidney Transplant: A potential option for eligible individuals with end-stage kidney disease
Frequently Asked Questions (FAQs)
What are the earliest signs of kidney failure?
Early signs can be subtle and include changes in urination patterns (more frequent urination, especially at night), foamy urine, and swelling in feet or ankles. As kidney failure progresses, symptoms become more pronounced.
Can you have kidney disease without any symptoms?
Yes. Many people with early chronic kidney disease have no or very mild symptoms. That’s why CKD is often called a “silent” disease until significant damage has occurred.
Is swelling always a sign of kidney failure?
Swelling can be due to many conditions, but in the context of reduced kidney function, it is a key symptom and warrants evaluation, especially when accompanied by changes in urination or fatigue.
What should I do if I notice blood in my urine?
Blood in the urine (hematuria) is never normal. Contact a healthcare professional immediately, as it can indicate severe kidney disease or other serious health problems.
Is kidney failure reversible?
Acute kidney injury can be reversible if treated quickly and effectively. Chronic kidney failure is generally progressive and irreversible, but its progression can often be slowed with proper treatment.
Key Takeaways
- Kidney failure can develop suddenly (acute) or slowly (chronic), with symptoms ranging from subtle urinary changes to severe complications like swelling, fatigue, and confusion.
- Prompt recognition of symptoms and timely medical intervention can prevent life-threatening complications and improve long-term outcomes.
- If you experience persistent or worsening symptoms of kidney failure, especially sudden changes in urination or severe swelling, seek medical attention immediately.
References
- https://www.healthdirect.gov.au/kidney-failure
- https://www.healthline.com/health/kidney-health/kidney-failure-symptoms
- https://www.medicalnewstoday.com/articles/327300
- https://www.medicalnewstoday.com/articles/172179
- https://www.healthline.com/health/video/kidney-failure
- https://aakp.org/programs-and-events/aakp-healthline/
- https://www.healthline.com/health/video/foods-to-avoid-with-kidney-disease
- https://www.kidney.org/kidney-topics/kidney-failure
Similar Articles
Read full bio of Sneha Tete
