The kidneys are a pair of fist-sized organs usually bean-shaped, located at the bottom of the rib cage in the lower middle of the back. There is one kidney on each side of the spine.
Kidneys are essential to having a healthy body. They are mainly responsible for filtering waste products, excess water, and other impurities out of the blood. They filter your blood 12 times per hour.
These toxins are stored in the bladder and then removed during urination. The kidneys are connected by tubes called ureters to the urinary bladder where urine containing toxins are stored. The bladder is connected to the outside of the body by another tube-like structure called the urethra.
The kidneys also regulate pH, salt, and potassium levels in the body. They produce hormones that regulate blood pressure and control the production of red blood cells. The kidneys even activate a form of vitamin D that helps the body absorb calcium.
Kidney failure occurs when your kidneys become damaged and lose the ability to filter waste from your blood sufficiently and can’t perform their other functions. This can either happen gradually if it’s chronic kidney disease or rapidly if it’s acute kidney failure.
Chronic kidney disease also known as chronic renal failure, chronic renal disease or chronic kidney failure, occurs when one suffers from gradual and usually permanent loss of kidney function over time. This happens gradually, usually over months to several years. It is much more widespread than people realise; it often goes undetected and undiagnosed until the disease is well advanced. Eventually, a person will develop permanent kidney failure.
It is not unusual for people to realize they have chronic kidney failure only when their kidney function is down to 25 percent of normal.
Chronic kidney disease is divided into five stages of increasing severity. The term "renal" is derived from the Latin name for kidney, so another name for kidney failure is "renal failure." Mild kidney disease is often called renal insufficiency.
The stages of chronic kidney disease are determined by the glomerular filtration rate. Glomerular filtration is the process by which the kidneys filter the blood, removing excess wastes and fluids. Glomerular filtration rate (GFR) is a calculation that determines how well the blood is filtered by the kidneys, a way to measure kidney function.
In the UK, and many other countries, kidney disease stages are classified as follows:
Stage 1 - GFR rate is normal. However, evidence of kidney disease has been detected.
Stage 2 - GFR rate is lower than 90 milliliters, and evidence of kidney disease has been detected.
Stage 3 - GFR rate is lower than 60 milliliters, regardless of whether evidence of kidney disease has been detected.
Stage 4 - GRF rate is lower than 30 milliliters, regardless of whether evidence of kidney disease has been detected.
Stage 5 - GFR rate is lower than 15 milliliters. Renal failure has occurred.
The majority of patients with chronic kidney disease rarely progress beyond Stage 2. It is important for kidney disease to be diagnosed and treated early for serious damage to be prevented.
Stage 5 chronic kidney disease is also referred to as kidney failure, end-stage kidney disease, or end-stage renal disease, wherein there is total or near-total loss of kidney function. There is dangerous accumulation of water, waste, and toxic substances, and most individuals in this stage of kidney disease need dialysis or transplantation to stay alive.
Unlike chronic kidney disease, acute kidney failure develops rapidly, over days or weeks.
Acute kidney failure usually develops in response to a disorder that directly affects the kidney, its blood supply, or urine flow from it.
Acute kidney failure is often reversible, with complete recovery of kidney function.
Some patients are left with residual damage and can have a progressive decline in kidney function in the future.
On occasion, patients who have acute kidney failure do not recover and irreversible kidney damage requires dialysis.
Causes of Chronic Kidney Disease
While chronic kidney disease sometimes results from primary diseases of the kidneys themselves, the major causes are diabetes and high blood pressure.
Often it's the result of a combination of different problems.
Chronic kidney disease can be caused by:
High blood pressure – over time, this can put strain on the small blood vessels in the kidneys and stop the kidneys working properly
Diabetes – too much glucose in your blood can damage the tiny filters in the kidneys
High cholesterol – this can cause a build-up of fatty deposits in the blood vessels supplying your kidneys, which can make it harder for them to work properly
Glomerulonephritis – kidney inflammation
Polycystic kidney disease – an inherited condition where growths called cysts develop in the kidneys
Blockages in the flow of urine – for example, from recurrent kidney stones or an enlarged prostate
Long-term, regular use of certain medicines – such as lithium and non-steroidal anti-inflammatory drugs (NSAIDs)
If one has any of the following conditions, they are at higher-than-normal risk of developing chronic kidney disease. One's kidney function may need to be monitored regularly.
Diabetes mellitus type 1 or type 2
High blood pressure
Sickle cell disease
Systemic lupus erythematosus
Vascular diseases such as arteritis, vasculitis, or fibromuscular dysplasia
Vesicoureteral reflux (a urinary tract problem in which urine travels from the bladder the wrong way back toward the kidney)
Require regular use of anti-inflammatory medications
A family history of kidney disease
It's a common condition often associated with getting older. Anyone can get it, although it's more common in black people and people of south Asian origin.
Signs and Symptoms of Kidney Disease
The kidneys are remarkable in their ability to compensate for problems in their function. That is why chronic kidney disease may progress without symptoms for a long time until only very minimal kidney function is left.
Because the kidneys perform so many functions for the body, kidney disease can affect the body in a large number of different ways. Symptoms vary greatly. Several different body systems may be affected. Notably, most patients have no decrease in urine output even with very advanced chronic kidney disease.
Signs and symptoms of chronic kidney disease include:
a reduced amount of urine,
need to urinate frequently, especially at night (nocturnal),
blood in urine or dark urine,
high blood pressure,
fatigue and weakness (from anaemia or accumulation of waste products in the body),
loss of appetite,
pale skin (from anaemia),
shortness of breath from fluid accumulation in the lungs,
oedema - swollen feet, hands, and ankles (face if oedema is severe),
decreased mental alertness,
pain on the side or mid to lower back,
numbness in the feet or hands (peripheral neuropathy),
restless legs syndrome,
chest pain due to pericarditis (inflammation around the heart),
bleeding (due to poor blood clotting),
bone pain and fractures,
decreased sexual interest and erectile dysfunction.
When to Seek Emergency Treatment
Several signs and symptoms may suggest complications of chronic kidney disease. One should call a health care professional if they notice any of the following symptoms:
change in energy level or strength;
increased water retention (puffiness or swelling) in the legs, around the eyes, or in other parts of the body;
shortness of breath or change from normal breathing;
nausea or vomiting;
bone or joint pain;
easy bruising; or
If a woman has known kidney problems, she should see a health care professional right away if she knows or suspects that she is pregnant.
See a health care practitioner as recommended for monitoring and treatment of chronic conditions such as diabetes, high blood pressure, and high cholesterol.
A doctor will check for signs and ask the patient about symptoms. The following tests may also be ordered:
Blood test - a blood test may be ordered to determine whether waste substances are being adequately filtered out. If levels of urea and creatinine are persistently high, the doctor will most likely diagnose end-stage kidney disease.
Urine test - a urine test helps find out whether there is either blood or protein in the urine.
Kidney scans - kidney scans may include a magnetic resonance imaging (MRI) scan, computed tomography (CT) scan, or an ultrasound scan. The aim is to determine whether there are any blockages in the urine flow. These scans can also reveal the size and shape of the kidneys - in advanced stages of kidney disease the kidneys are smaller and have an uneven shape.
Kidney biopsy - a small sample of kidney tissue is extracted and examined for cell damage. An analysis of kidney tissue makes it easier to make a precise diagnosis of kidney disease.
Chest X-ray - the aim here is to check for pulmonary edema (fluid retained in the lungs).
Glomerular filtration rate (GFR) - GFR is a test that measures the glomerular filtration rate - it compares the levels of waste products in the patient's blood and urine. GFR measures how many milliliters of waste the kidneys can filter per minute. The kidneys of healthy individuals can typically filter over 90 ml per minute.
Chronic Kidney Disease Treatment
There is no cure for chronic kidney disease. The four goals of therapy are to: