Chronic renal failure results in the complete or near complete failure of the kidneys to perform their functions. These include regulating fluid balance in the body, removing waste products and producing and concentrating urine, among other functions. At this point the patient will need dialysis or a kidney transplant to survive. Symptoms from kidney failure are widespread, owing to the major effect the kidneys have on general bodily function.
Anemia
The kidneys are responsible for the secretion of a hormone known as erythropoietin (EPO). EPO serves to regulate red blood cell production and as a result of chronic renal failure, its production is severely decreased. This results in the bone marrow producing fewer red blood cells with resulting anemia. Patients with renal failure on dialysis can also become anemic due to the loss of blood during the procedure in addition to loss of nutrients such as folic acid and iron that are important components of red blood cells.
Bone Disease
One of the main functions of the kidney is to regulate the balance of substances such as vitamin D, calcium and phosphate. Failure of the kidneys leads to abnormal levels of these substances and bone disease can result. If left untreated, the bones can become weak and thin with resulting weakness and pain. Patients with renal bone disease are at a higher risk of osteoporosis and bone fractures.
Metabolic Issues
The kidney is one of the main sites where substances like potassium are excreted. Kidney failure can result in potassium buildup, which has toxic effects on heart tissue. Resulting disturbances of heart rhythm and rate can result which must be treated promptly. In addition, high potassium levels can cause muscle weakness. The kidney also serves to excrete hydrogen ions; when they build up in kidney failure, acidosis of the blood stream can develop. This presents with general symptoms such as weakness and malaise.
Swelling
Patients with kidney failure will often note swelling of the abdomen and lower limbs. The kidney is a primary site of fluid balance regulation; with kidney failure, there is often a buildup of fluid in the body. Increased fluid in the blood vessels often results in the fluid "pushing out" into spaces of the body such as the abdomen or tissues in the lower limbs with ensuing swelling.
Uremia Buildup
Uremia is one of the toxins in the blood stream that is removed by normally functioning kidneys. Kidney failure often results in the buildup of uremia with many effects. Uremia is toxic to the platelet cells in the blood which aids in the clotting system; as a result of platelet dysfunction there is a greater propensity of the body to bruise and/or bleed. It can also inflame the pericardium (sac which encloses the heart) causing pericarditis with symptoms of chest pain and discomfort. Increased uremia also has toxic effects on the brain and nervous system with symptoms of lethargy, decreased mental acuity, and even coma. Nervous system effects include peripheral nerve effects such as loss of reflexes, impaired sensation and autonomic effects such as impaired heart rate and blood pressure variability. Uremia buildup in the skin can also result in constant itching (known as pruritus).
Depression
The patient can have a depressed mood when suffering from chronic kidney disease for a variety of different reasons. Toxic metabolite buildup can result in altered mood, general malaise, weakness and decreased mental function. In addition, the patient must accept a new schedule and lifestyle when kidney failure is imminent and the psychological impact can be huge.
Restless Leg Syndrome
Patients with kidney failure tend to have an aching, jittery feeling of restlessness that results in urges to kick or thrash the legs, especially at night. This can interfere with both the patient's sleep and his partner's sleep. It is theorized that buildup of toxic chemicals and nerve damage contribute to this problem.
References
- "Clinics in Geriatric Medicine;" Clinical Presentation of Renal Failure in the Aged: Chronic Renal Failure; Jassal, SV. Volume 25, August 2009.
- "Cecil Medicine, 23rd Edition;" Goldman; 2007
- "Brenner and Rector's The Kidney, 8th Edition;" Brenner; 2007
