Uremia

Overview

Uremia is the term for a dangerous buildup of waste products, fluid, and chemicals in the blood that occurs when the kidneys can no longer filter them out. The kidneys normally remove waste such as urea and creatinine, balance fluids and minerals, and help control blood pressure. When kidney function drops severely, these wastes accumulate and begin to affect nearly every system in the body.

Uremia is a sign of advanced kidney failure, whether from a sudden (acute) injury or long-standing (chronic) kidney disease. It is a serious, potentially life-threatening condition that requires urgent medical care. With treatment, usually dialysis or a kidney transplant, the toxic effects can be reversed or controlled and many people live for years.

The word uremia literally means urine in the blood, reflecting the buildup of substances the kidneys would normally pass out in urine. Because these wastes touch every organ system, the illness can show up in many different ways at once, from the skin and nerves to the heart and brain. This is why uremia is treated as a serious, whole-body problem rather than a single symptom.

Symptoms

Because waste affects the whole body, symptoms are wide-ranging and tend to worsen as kidney function declines.

• Persistent fatigue and weakness
• Loss of appetite, nausea, and vomiting
• A metallic taste in the mouth or ammonia-like breath
• Itching all over the skin
• Trouble concentrating, confusion, or, in severe cases, drowsiness and seizures
• Muscle cramps and restless legs
• Swelling in the legs, feet, or around the eyes
• Shortness of breath from fluid buildup

Severe confusion, seizures, chest pain, or difficulty breathing are emergencies that require immediate care.

Causes

Uremia is caused by a major loss of kidney filtering ability. Underlying causes include:

• Chronic kidney disease: Long-term damage from diabetes, high blood pressure, or other kidney conditions that slowly destroys filtering capacity.
• Acute kidney injury: A sudden drop in kidney function from severe dehydration, blood loss, infection, certain medications, or a blockage of urine flow.
• Obstruction: Blockage of the urinary tract, for example by stones or an enlarged prostate, that backs up and damages the kidneys.

As filtering falls, waste products that the kidneys should clear instead accumulate in the bloodstream.

Risk Factors

• Diabetes
• High blood pressure
• Existing chronic kidney disease
• Heart failure
• Recurrent kidney infections or stones
• Use of medications that can harm the kidneys
• Older age and a family history of kidney disease

Diagnosis

Uremia is diagnosed through blood and urine tests that show how poorly the kidneys are working, alongside the symptoms.

• Blood tests: Elevated urea (BUN) and creatinine, and a reduced estimated filtration rate (eGFR), indicate kidney failure.
• Electrolyte and acid tests: To detect dangerous levels of potassium and acid buildup.
• Urine tests: To assess kidney function and look for causes.
• Imaging: Ultrasound to check the size of the kidneys and look for blockages.

Treatment

Treatment removes accumulated waste, corrects chemical imbalances, and addresses the underlying cause.

• Dialysis: A treatment that filters the blood when the kidneys cannot, often the immediate, life-saving step in severe uremia.
• Treating the cause: Relieving an obstruction, stopping harmful medications, treating infection, or restoring fluids in acute injury.
• Managing complications: Lowering high potassium, correcting acid buildup, controlling blood pressure, and treating anemia.
• Kidney transplant: The long-term treatment for many people with permanent kidney failure.
• Diet and medication: A kidney-friendly diet and medicines help control symptoms and slow further damage.

Prevention

• Control diabetes and blood pressure, the leading causes of kidney disease
• Have kidney function checked regularly if you are at risk
• Stay well hydrated and avoid unnecessary kidney-harming medications
• Use over-the-counter pain relievers like NSAIDs sparingly if you have kidney concerns
• Follow your care plan closely if you already have kidney disease

When to See a Doctor

See a doctor promptly if you have known kidney disease and develop worsening fatigue, nausea, swelling, itching, or trouble concentrating. Seek emergency care immediately for severe confusion, seizures, chest pain, severe shortness of breath, or a near-total drop in urine output, as these signal life-threatening kidney failure that needs urgent treatment. People with risk factors such as diabetes or high blood pressure should have regular kidney function testing even without symptoms.

Related Topics

Frequently Asked Questions

References

1. National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK). Kidney Failure.
2. MedlinePlus, U.S. National Library of Medicine. Chronic kidney disease.
3. Mayo Clinic. Chronic kidney disease — Symptoms and causes.
4. National Kidney Foundation. Uremia and kidney failure.