Chronic Kidney Disease: Symptoms and Diagnosis

In chronic kidney disease (CKD), kidney function gradually declines over months to years. In the early stages of CKD, most patients remain relatively without symptoms as their bodies compensate and get used to the metabolic derangements that develop over time. When the kidney function becomes severely impaired, symptoms due to the accumulation of toxins and fluids start to develop.

What are the symptoms of chronic kidney disease?

Symptoms of CKD vary depending on the severity of the kidney damage. CKD is divided into five stages based on the level of kidney function or glomerular filtration rate (GFR). GFR can be estimated from blood levels of creatinine and is normally greater than 90 ml/min.

CKD Stage 1 (kidney function 90-100 %)

In Stage 1 CKD, the GFR is greater than 90 ml/min/1.73 m² but there are laboratory abnormalities like protein in the urine; evidence of structural damage to the kidneys on x-ray, ultrasound, MRI, or CT scan; or a family history of polycystic kidney disease. Patients are usually asymptomatic.

CKD Stage 2 (kidney function 60-89%)

In Stage 2 or mild CKD, the GFR is 60 – 89 ml/min/1.73 m². Patients are usually asymptomatic but some may complain of frequent urination especially at night, high BP, urine abnormalities on urinalysis with normal or slightly high serum creatinine.

National Kidney Foundation Kidney Disease Outcomes Quality Initiative (NKF-K/DOQI) Clinical Practice Guideline for Chronic Kidney Disease

CKD Stage 3 (kidney function 30-59%)

In Stage 3 or moderate CKD, the GFR is 30-59 ml/min/1.73 m² . The patient may still be asymptomatic or start having mild symptoms. There may be urinary abnormalities present and serum creatinine is elevated

CKD Stage 4 (kidney function 15-29%)

In Stage 4 CKD, GFR is 15-29 ml/min/1.73 m² . Symptoms may be mild, vague and nonspecific, or very severe, depending on the underlying cause of kidney failure and associated illnesses.

CKD Stage 5 (kidney function less than 15%)

Stage 5 is very severe CKD with GFR of < 15 ml/min/1.73 m² . Also called End Stage Kidney Disease, most patients will need dialysis or kidney transplantation at this stage. Symptoms may vary from moderate to severe, with life-threatening complications.

Therapy, sign symptoms of kidney failure increase and most of the patients need dialysis or kidney transplantation

Common symptoms of kidney diseases

• Loss of appetite, nausea and vomiting.
• Weakness, fatigue and weight loss.
• Swelling (edema) of lower legs.
• Swelling of face or around the eyes especially in the morning.
• High blood pressure, especially if severe, uncontrolled or in young individuals.
• Pallor.
• Sleep problems, lack of concentration and dizziness.
• Itching, muscle cramps or restlessness.
• Flank pains.
• Frequent urination especially at night (nocturia).
• Bone pains and fractures in adults and retarded growth in children.
• Decreased sexual drive and erectile dysfunction in males and menstrual disturbances in females.

When to suspect CKD in a person suffering from high blood pressure?

In persons with high blood pressure (hypertension) suspect CKD if:

• Age is less than 30 or more than 50 at the time of diagnosis of hypertension.
• Severe hypertension at the time of diagnosis (i.e. more than 200/ 120 mm of Hg).
• Severe uncontrolled high blood pressure even with regular treatment
• Concomitant visual disturbances.
• Presence of protein in urine.
• Presence of symptoms suggesting CKD such as presence of swelling, loss of appetite, weakness etc.

What are the complications of advanced CKD?

Potential complications of advanced CKD are:

• Severe difficulty in breathing and chest pain due to marked fluid retention in the lungs (pulmonary edema).
• Severe high blood pressure.
• Severe nausea and vomiting.
• Severe weakness
• Central nervous system complications: confusion, extreme sleepiness, convulsion and coma.
• High levels of potassium in the blood (hyperkalemia) which could impair the heart’s ability to function and could be life-threatening.
• Pericarditis, an inflammation of the sac-like membrane that envelopes the heart (pericardium).

Diagnosis of CKD

CKD is commonly asymptomatic in early stages. Usually, CKD is initially diagnosed when hypertension is detected, a blood test showing elevated serum creatinine is requested or urine tests positive for albumin. A person must be screened for CKD if he is at high risk for developing kidney damage (diabetic, hypertensive, older age, family history of CKD).

Hemoglobin

Hemoglobin levels are usually low. Anemia is due to decreased erythropoietin production by the kidney.

Urine test

Albumin or protein in the urine (called albuminuria or proteinuria) is an early sign of CKD. Even small amounts of albumin in the urine, called microalbuminuria, may be the earliest sign of CKD. Since proteinuria can be also due to fever or heavy exercise, it is best to exclude other causes of proteinuria before diagnosing CKD.

Serum creatinine, blood urea nitrogen and eGFR

An easy and inexpensive way to measure kidney function is a blood level of creatinine. Together with age and sex, the serum creatinine is used in many formulas to estimate kidney function or glomerular filtration rate (eGFR). Regular monitoring of creatinine helps to assess progression and treatment response in CKD. On the basis of eGFR, CKD is divided into five stages. This staging is useful to recommend additional testing and suggestions for proper management.

Ultrasound of the kidney

The ultrasound is a simple, effective and inexpensive test in the diagnosis of CKD. Shrunken kidneys are diagnostic of chronic kidney disease. However, normal or even large kidneys are seen in CKD caused by adult polycystic kidney disease, diabetic nephropathy and amyloidosis. Ultrasound is also helpful to diagnose CKD due to urinary obstruction or kidney stones.

Other tests

CKD causes disturbances in different functions of the kidneys. To evaluate these disturbances different tests are performed such as: tests for electrolyte and acid-base balance (sodium, potassium, magnesium, bicarbonate), tests for anemia (hematocrit, ferritin, transferrin saturation, peripheral smear), tests for bone disease (calcium, phosphorus, alkaline phosphatase, parathyroid hormone), other general tests (serum albumin, cholesterol, triglycerides, blood glucose and hemoglobin A1c) and ECG and echocardiography.

When should a patient with CKD contact the doctor?

Patients with CKD should contact the doctor immediately, if he or she develops:

• Rapid unexplained weight gain, marked reduction in urine volume, aggravation of swelling, shortness of breath or difficulty in breathing while lying down in bed.
• Small and contracted kidneys, seen on ultrasound, are the hallmark sign of chronic kidney disease.
• Chest pain, very slow or fast heart rate.
• Fever, severe diarrhea, severe loss of appetite, severe vomiting, blood in vomiting or unexplained weight loss.
• Severe muscle weakness of recent origin.
• Development of confusion, drowsiness or convulsion.
• Recent worsening of well controlled high blood pressure.
• Red urine or excessive bleeding.

Source: Kidney Education Foundation