ConditionKidneys & urinary tract
Uremic Syndrome (Uremia)
Uremic syndrome, or uremia, is the set of symptoms caused by waste products building up in the blood when the kidneys can no longer filter it, usually in advanced chronic kidney disease or severe acute kidney injury. Symptoms include tiredness, nausea and vomiting, loss of appetite, itching, a metallic taste, muscle cramps, swelling, confusion and, in severe cases, seizures, bleeding and inflammation around the heart. Dialysis or a kidney transplant removes the toxins, and uremic symptoms are a key reason to start dialysis.
Also called: Uremia, uremic toxicity, azotemia with symptoms, end-stage kidney disease symptoms
At a glance
- What it is
- Illness caused by toxins accumulating when kidney function falls to very low levels.
- Main causes
- End-stage chronic kidney disease, severe acute kidney injury.
- Symptoms
- Fatigue, nausea, vomiting, poor appetite, itching, confusion, cramps, swelling, breathlessness.
- Severe signs
- Seizures, chest pain from pericarditis, bleeding, coma.
- Treatment
- Dialysis, kidney transplant, or conservative kidney care.
When to get help
Call 911 or go to the ER
- Confusion, extreme drowsiness, seizures or muscle twitching in someone with kidney failure
- Chest pain worse when lying down or breathing in, or breathlessness at rest
- Very weak, slow or irregular heartbeat, or severe muscle weakness (possible high potassium)
- Little or no urine with swelling and breathlessness
See a doctor within a day or two
- Persistent vomiting and inability to eat or drink
- New bleeding, such as nosebleeds or black stools, in advanced kidney disease
- Missed dialysis sessions with worsening symptoms
Book a routine appointment
- Worsening fatigue, poor appetite, itching or a metallic taste in someone with chronic kidney disease
- Trouble sleeping, restless legs or numbness in the feet with kidney disease
What causes uremia
When kidney function, measured as estimated glomerular filtration rate (eGFR), falls below about 15 mL/min (kidney failure), substances normally removed in urine accumulate. Urea is one marker, but many other toxins, acids, potassium, phosphate and fluid also build up, and hormones made by the kidney decrease.
Causes include:
- chronic kidney disease progressing to kidney failure: most often from diabetes and high blood pressure
- acute kidney injury from severe infection, dehydration, medicines, toxins or blockage
- glomerulonephritis, polycystic kidney disease and other kidney diseases
- urinary tract obstruction
Symptoms
Symptoms usually come on gradually and are often vague at first.
| System | Symptoms |
|---|---|
| General | Fatigue, weakness, feeling cold, weight loss |
| Digestive | Nausea, vomiting, loss of appetite, metallic taste, ammonia-smelling breath, hiccups |
| Skin | Itching, dry skin, yellow-gray tone, easy bruising; rarely white crystals on the skin ("uremic frost") |
| Brain and nerves | Poor concentration, confusion, sleep problems, restless legs, numbness and tingling (uremic neuropathy), muscle twitching, seizures |
| Heart and lungs | Swelling, breathlessness from fluid, high blood pressure, chest pain from pericarditis |
| Blood | Anemia, bleeding tendency from poorly functioning platelets |
| Muscles and bones | Cramps, weakness, bone pain |
| Reproductive | Low libido, irregular periods |
Diagnosis
- blood tests: creatinine and eGFR, urea (BUN), potassium, bicarbonate, calcium, phosphate, blood count
- urine tests: protein and blood
- kidney ultrasound: kidney size and blockage
- ECG for high potassium effects and pericarditis
- echocardiogram if pericarditis is suspected
Uremia is a clinical diagnosis: the combination of very low kidney function with symptoms attributable to it.
Treatment
Dialysis
Dialysis filters the blood and removes toxins and excess fluid. Uremic symptoms, high potassium, severe acidosis, fluid overload and pericarditis are common reasons to start.
- hemodialysis: usually 3 times a week at a center, or more often at home
- peritoneal dialysis: done daily at home using the lining of the abdomen as a filter
Kidney transplant
A transplant offers the best long-term outcome for many people, restoring kidney function and resolving uremia. It can be from a living or deceased donor, and pre-emptive transplant before dialysis is possible.
Conservative kidney management
Some people, especially older adults with other serious illnesses, choose not to have dialysis. Conservative care focuses on symptom control: medicines for itching, nausea and fluid, diet changes, anemia treatment and palliative support.
Supportive treatment
- diet: limiting potassium, phosphate, salt and fluid as advised; adequate protein
- phosphate binders, vitamin D and treatments for bone health
- erythropoiesis-stimulating agents and iron for anemia
- medicines for itching (such as difelikefalin for people on hemodialysis) and nausea
- avoiding medicines that are harmful or accumulate in kidney failure, such as NSAIDs
Complications
- hyperkalemia and dangerous heart rhythms
- metabolic acidosis
- uremic pericarditis and fluid around the heart
- uremic encephalopathy, seizures and coma
- bleeding
- malnutrition
- death if untreated
Frequently asked questions
What are the symptoms of uremia?
Common symptoms are tiredness, nausea, vomiting, poor appetite, a metallic taste, itching, muscle cramps, swelling, trouble concentrating and sleep problems. Severe uremia can cause confusion, seizures, chest pain from pericarditis and bleeding.
What causes uremic syndrome?
It is caused by kidney failure, either from advanced chronic kidney disease, often due to diabetes or high blood pressure, or from severe acute kidney injury. When the kidneys fail, waste products and fluid accumulate in the body.
Can uremia be reversed?
Yes. Dialysis or a kidney transplant removes the toxins and usually improves symptoms within days to weeks. If uremia is caused by acute kidney injury, it may reverse as the kidneys recover.
How long can you live with uremia without dialysis?
Without dialysis or transplant, severe uremia from kidney failure is fatal, often within weeks to months, though it varies. Some people choose conservative kidney care focused on comfort, which can provide good quality of life for a period.
Sources
This guide was written from current patient and clinical guidance, including:
- National Kidney Foundation: Kidney failure (ESRD) causes, symptoms and treatments
- Kidney Disease: Improving Global Outcomes (KDIGO): Clinical practice guideline for the evaluation and management of CKD
- NIDDK: Kidney failure: choosing a treatment
- MedlinePlus: Uremia; End-stage kidney disease
- American Society of Nephrology: Kidney failure resources