When kidneys begin to fail due to chronic kidney disease, the body experiences a range of complications. Understanding these symptoms and what to expect is crucial for individuals and their caregivers. Your kidneys are truly 'multi-taskers' of the body, performing many vital functions beyond just filtering waste. When their ability to function diminishes, the effects can ripple throughout nearly every system.

To better understand the chronic kidney disease symptoms and what happens when the kidneys no longer function properly, we will use the mnemonic WAVE: Waste, Acid/Base, Volume, and Endocrine. This framework provides a clear way to categorize the diverse impacts of chronic kidney disease on your health.

Waste Accumulation (W)

Failure to remove waste products from the body results in uremia, a general term for the condition where kidneys cannot clear toxic waste products. People with uremia may experience a loss of appetite, nausea, vomiting, severe generalized itching (pruritus), sexual and reproductive dysfunction, or bleeding due to decreased numbers of platelets.

Long-term kidney failure can affect the neurologic system, leading to symptoms such as fatigue, lethargy, restless legs, muscle weakness, loss of sensation, confusion, seizures, decreased consciousness, or even coma. The gastrointestinal system can also be impacted, causing anorexia (loss of appetite), nausea, vomiting, and malnutrition (low serum albumin levels).

Cardiovascular effects might include pericarditis (inflammation of the heart lining), chest pain, low blood pressure, heart failure, and cardiac arrest due to extremely irregular heartbeats. Pulmonary (lung) effects can manifest as chest pain, pleural effusion (fluid buildup around the lungs), and shortness of breath, potentially leading to severe complications. The skeletal system is also affected, with implications for bone breakdown. Managing severe uremia often requires replacement therapy like dialysis or kidney transplantation.

Acid/Base and Electrolyte Imbalances (A)

When kidneys do not excrete hydrogen ions or acid and fail to generate bicarbonate, an acidosis develops. This abnormally high acid level can interfere with protein metabolism, increase bone breakdown, and lead to further kidney injury. Normal kidneys also maintain proper levels of electrolytes such as potassium, calcium, and phosphorus.

When kidneys fail, excess potassium can accumulate, causing muscle weakness, a slow heart rate, and serious, potentially fatal heart arrhythmias. Ways to manage potassium abnormalities include avoiding high-potassium foods, taking diuretics, or medications like Polystyrene sulfonate. People on hemodialysis must carefully monitor dietary potassium, while those on peritoneal dialysis have fewer restrictions due to daily treatments. All individuals with CKD must have their potassium levels closely monitored by their medical team.

Calcium and phosphate imbalances are also common, leading to increased parathyroid hormone, skeletal and muscle breakdown, and decreased circulation to skin and other organs (calciphylaxis) caused by blood-vessel disease. Ways to manage these include avoiding high-phosphate foods, taking sodium bicarbonate supplements, phosphate binders (such as calcium acetate or non-calcium binders), Vitamin D supplements, or agents like Sinacalcet to control parathyroid hormone. Bicarbonate or lactate solutions can also be added to dialysis treatments.

Volume Imbalances (V)

Kidneys are critical for regulating the body's sodium (salt) and water volume. When they fail, severe salt and water imbalances occur because excess salt is not filtered out, causing the body to retain water. This fluid retention can manifest in body tissues as swelling (edema) in the feet, legs, face, and hands.

Fluid can also accumulate around the lungs (pleural effusion) or in the abdomen (ascites). This fluid overload can lead to hypertension (high blood pressure) and congestive heart failure, where fluid builds up in the lungs due to the heart's inability to pump effectively. Management strategies include reducing salt and fluid in the diet, taking diuretic medications, or initiating dialysis treatments. Hemodialysis allows for precise fluid removal during treatments, while peritoneal dialysis prescriptions are adjusted based on accumulated fluid.

Endocrine Hormonal Abnormalities (E)

Finally, diseased kidneys reduce or stop the production and activation of essential hormones. Activated Vitamin D levels decrease, which can cause calcium to be drawn from bones (hypocalcemia), leading to bone deterioration and stimulating the parathyroid gland to produce too much hormone (hyperparathyroidism). Ways to raise Vitamin D levels back to normal include intravenous or oral supplements.

Additionally, erythropoietin, a hormone manufactured in the kidneys that helps make red blood cells, decreases. This reduction causes anemia, leading to muscle weakness and fatigue. Anemia management involves administering erythropoietin medication (intravenously or subcutaneously) and ensuring adequate iron levels, which can be supplemented orally or intravenously.