What Happens to the Body if Your Kidneys Fail??
Kidney failure, also known as renal failure or renal insufficiency, is a medical condition of impaired kidney function in which the kidneys fail to adequately filter metabolic wastes from the blood.
The two main forms are acute kidney injury, which is often reversible with adequate treatment, and chronic kidney disease, which is often not reversible. In both cases, there is usually an underlying cause.
Kidney failure is mainly determined by a decrease in glomerular filtration rate, which is the rate at which blood is filtered in the glomeruli of the kidney.
The condition is detected by a decrease in or absence of urine production or determination of waste products (creatinine or urea) in the blood. Depending on the cause, hematuria (blood loss in the urine) and proteinuria (protein loss in the urine) may be noted.
In kidney failure, there may be problems with increased fluid in the body (leading to swelling), increased acid levels, raised levels of potassium, decreased levels of calcium, increased levels of phosphate, and in later stages anemia. Bone health may also be affected.
Long-term kidney problems are associated with an increased risk of cardiovascular disease.
Kidney failure can be divided into two categories: acute kidney injury or chronic kidney disease.
The type of renal failure is differentiated by the trend in the serum creatinine; other factors that may help differentiate acute kidney injury from chronic kidney disease include anemia and the kidney size on sonography as chronic kidney disease generally leads to anemia and small kidney size.
Acute kidney injury
Acute kidney injury (AKI), previously called acute renal failure (ARF), is a rapidly progressive loss of renal function, generally characterized by oliguria (decreased urine production, quantified as less than 400 mL per day in adults, less than 0.5 mL/kg/h in children or less than 1 mL/kg/h in infants); and fluid and electrolyte imbalance.
AKI can result from a variety of causes, generally classified as prerenal, intrinsic, and postrenal.
The underlying cause must be identified and treated to arrest the progress, and dialysis may be necessary to bridge the time gap required for treating these fundamental causes.
Chronic kidney disease (CKD) can also develop slowly and, initially, show few symptoms.
CKD can be the long term consequence of irreversible acute disease or part of a disease progression.
Acute-on-chronic kidney failure
Acute kidney injuries can be present on top of chronic kidney disease, a condition called acute-on-chronic kidney failure (AoCRF).
The acute part of AoCRF may be reversible, and the goal of treatment, as with AKI, is to return the patient to baseline kidney function, typically measured by serum creatinine.
Like AKI, AoCRF can be difficult to distinguish from chronic kidney disease if the patient has not been monitored by a physician and no baseline (i.e., past) blood work is available for comparison.
Signs and symptoms
Symptoms can vary from person to person. Someone in early stage kidney disease may not feel sick or notice symptoms as they occur.
When kidneys fail to filter properly, waste accumulates in the blood and the body, a condition called azotemia. Very low levels of azotaemia may produce few, if any, symptoms.
If the disease progresses, symptoms become noticeable (if the failure is of sufficient degree to cause symptoms). Kidney failure accompanied by noticeable symptoms is termed uremia.
Symptoms of kidney failure include the following:
High levels of urea in the blood, which can result in:
Vomiting and/or diarrhea, which may lead to dehydration
More frequent urination, or in greater amounts than usual, with pale urine
Less frequent urination, or in smaller amounts than usual, with dark coloured urine
Blood in the urine
Pressure, or difficulty urinating
Unusual amounts of urine, usually in large quantities
A buildup of phosphates in the blood that diseased kidneys cannot filter out may cause:
Nonunion in broken bones
Muscle cramps (caused by low levels of calcium which can be associated with hyperphosphatemia)
A buildup of potassium in the blood that diseased kidneys cannot filter out (called hyperkalemia) may cause:
Abnormal heart rhythms
Failure of kidneys to remove excess fluid may cause:
Swelling of the legs, ankles, feet, face and/or hands
Shortness of breath due to extra fluid on the lungs (may also be caused by anemia)
Acute kidney injury (previously known as acute renal failure) - or AKI - usually occurs when the blood supply to the kidneys is suddenly interrupted or when the kidneys become overloaded with toxins.
Causes of acute kidney injury include accidents, injuries, or complications from surgeries in which the kidneys are deprived of normal blood flow for extended periods of time. Heart-bypass surgery is an example of one such procedure.
Drug overdoses, accidental or from chemical overloads of drugs such as antibiotics or chemotherapy, may also cause the onset of acute kidney injury.
Unlike chronic kidney disease, however, the kidneys can often recover from acute kidney injury, allowing the patient to resume a normal life.
People suffering from acute kidney injury require supportive treatment until their kidneys recover function, and they often remain at increased risk of developing future kidney failure.
Chronic kidney disease
Chronic kidney disease (CKD) has numerous causes. The most common causes of CKD are diabetes mellitus and long-term, uncontrolled hypertension.
Polycystic kidney disease is another well-known cause of CKD. The majority of people afflicted with polycystic kidney disease have a family history of the disease. Other genetic illnesses affect kidney function, as well.
Overuse of common drugs such as ibuprofen, and acetaminophen (paracetamol) can also cause chronic kidney damage.
Some infectious disease agents, such as hantavirus, can attack the kidneys, causing kidney failure.
Stages of Kidney Failure
Chronic kidney failure is measured in five stages, which are calculated using a patientís GFR, or glomerular filtration rate.
Stage 1 CKD is mildly diminished renal function, with few overt symptoms.
Stages 2 and 3 need increasing levels of supportive care from their medical providers to slow and treat their renal dysfunction.
Patients in stages 4 and 5 usually require preparation of the patient towards active treatment in order to survive.
Stage 5 CKD is considered a severe illness and requires some form of renal replacement therapy (dialysis) or kidney transplant whenever feasible.
A whole food, plant-based diet may help some people with kidney disease. A high protein diet from either animal or plant sources appears to have negative effects on kidney function at least in the short term.