To know about kidney diseases, it would be easier if we knew about the kidneys first.
About the kidneys
The kidneys are two bean-shaped organs located behind your abdominal cavity. They work together to achieve their objectives and when one kidney’s function is impaired, the other kidney usually compensates for it and does most of the work such that the individual wouldn’t even develop any symptoms of impairment in kidney impairment. By the time an individual develops clinical features of kidney failure, then the two kidneys have been affected badly by the insult that has caused them to fail.
The kidneys make one to two litres of urine per day on the average in adults. However, the normal volume of urine produced is also dependent on your weight and volume of water taken within the period of time. The kidneys require water to adequately perform its function hence the need to take at least three litres of water per day.
Your water requirements will increase if you are in a place with high humidity or very hot weather because you get to lose more fluid from just breathing (insensible water loss) as well as from sweating and other daily activities. More so, if you are exercising (running, dancing, cycling, hiking or working out in the gym or at home), your water requirement increases.
Functions of the kidney
These organs work together mainly to
- maintain the various salts (electrolytes) in our bodies to be within a specific range thereby maintaining our blood pressures
- remove waste or harmful unwanted substances from our system.
- Converts inactive vitamin D3 to the active form in the kidneys. This active form of vitamin D3 regulates calcium balance in the body.
- Produce a substance that stimulates the bone marrow to make red blood cells and some of the insulin in our blood is broken down in the kidneys.
- Up to 25% of the blood from the heart passes through the kidneys every minute to be cleaned of unwanted substances which are then filtered and passed out as urine.
- The kidneys produce urine which flows through the ureters (two ureters, one arising from each kidney) into a single urinary bladder where the urine is stored and when full you feel the urge to pass urine, the bladder squeezes itself (contracts) to release the urine through the urethra. The bladder is connected to a Urethra through which urine passes when you go to the loo.
Glucose in Urine
Excess water is reabsorbed while essential salts and other important contents of the blood such as glucose and amino acids are reabsorbed into the body. However, if the level of glucose in the blood surpasses what the kidney can conveniently reabsorb, then some of the glucose will escape being reabsorbed and will be passed out in urine. This is seen in people who are diabetic particularly those with poor glucose control.
What happens when the kidneys don’t work?
When there is a disease of the kidney, some or all of these functions of the kidney become compromised. This is the point at which the person is said to have kidney disease.
Types of kidney disease
Kidney failure is said to be
- acute kidney injury
- chronic kidney disease
Acute kidney injury
Acute kidney failure (or acute kidney injury as it is called in medical parlance) from any cause may progress to chronic renal failure and end-stage renal disease. Prompt treatment of acute renal failure may help reduce risk of progression to chronic kidney disease or chronic renal failure.
What cause Acute kidney injury (AKI)?
Depleted fluid in the body due to excessive fluid loss and/ or inadequate fluid intake.
These may result from problems such as:
- Bleeding excessively for instance following childbirth, injury, or any cause of excessive bleeding
- Polyuria (passage of large volumes of urine)
If you are losing more fluid than usual either due to fever, diarrhoea, vomiting, excessive passing of urine (from an infection or any other illness), then you need to replenish not only the water but the electrolytes being lost through your gastrointestinal tract and urinary tract.
Use of substances that are toxic to the kidneys
These toxic substances include:
Some medications that are excreted by the kidneys. Some pain killers for example non-steroidal anti-inflammatory drugs NSAIDS like ibuprofen are known to cause damage to the kidneys by causing the blood vessels that supply them to constrict longer than necessary thereby damaging the kidneys. This damage is much worse in people taking these analgesics daily for weeks and even months. It is advisable to always consult your doctor for any type of pain that has persisted beyond three days despite the use of over-the-counter analgesics.
Some so called “food supplements” may contain toxic substances which may o may not be captured in the drug labels.
Traditional or unorthodox mixture/ concoctions and herbal medicines: these mostly contain unknown substances in unspecified doses. For the most part people taking it do not know the actual contents of the mixtures. Some of these are taunted as mixtures that heal every kind of disease and also make the healthy even healthier.
-Certain soaps and body creams also contain harmful substances in high doses which are absorbed into the blood stream through the skin and cause damage to the kidney. This may eventually culminate in kidney failure.
Obstruction to the outflow of urine along the urinary tract
- A mass in the pelvis such as an enlarged prostate gland, multiple uterine fibroids, ovarian tumour
- A stone along the urinary tract
- A narrow urethra resulting from either trauma to the urethra during a fall or some medical procedures that involve passing of instruments through the urethra.
- Cancer of the bladder or cervix (the neck of the womb) can also cause obstruction of urine flow
When there is an obstruction to outflow of urine, there is a back pressure effect which then damages the kidney such that it eventually reduces and or halts urine production. It is more like what happens when a pipe carrying water to a particular location is blocked, water will eventually stop flowing at the location.
The first thing that may be noticed is that the tap starts flowing really slowly, that is because the water begins to flow at higher pressures in order to get to the mains despite the obstruction. If the obstruction is not removed, one of two things happen: the water storage facility or tank might begin to overflow or the pipe bursts. Either way, water must find a way to flow, this is similar to what happens in our bodies.
However, in the human body, the water pipe (ureters) are unlikely to burst but will start to get wider than normal and then the kidneys reduce the amount of urine produced because the storage facility (urinary bladder) is full and cannot be emptied due to the obstruction. Sometimes, there might be an overflow from the urinary bladder –Overflow incontinence.
When there is an obstruction, the individual begins to have the following symptoms
- Straining to pass urine
- Hesitancy: takes some time before urine starts to flow while in the toilet.
- Passing little quantities at a time, with feeling that there is still more urine in the bladder
- Poor urine stream in men
- Pain in loin, blood in urine and passing of stones in urine (in persons who have kidney stones)
- Lower abdominal pain and swelling
- Inability to pass urine despite the feeling of bladder fullness.
Chronic kidney disease
A person is said to have chronic kidney disease (CKD) if they have had kidney failure and its symptoms for at least three months. It may be caused by an acute kidney injury that has progressed into a chronic one.
Causes of kidney disease
- High blood pressure – Hypertensive nephropathy-Read complications of hypertension to see how hypertension can cause chronic kidney disease.
- Diabetes – Diabetic nephropathy-Read complications of diabetes to see how hypertension can cause chronic kidney disease.
- High cholesterol – Cholesterol build-up in the blood vessels which supply your kidneys can cause CKD
- kidney infections
- Kidney inflammation (glomerulonephritis)
- Nephrotic syndrome
- Infections: HIV, cytomegalovirus, Epstein Barr virus, hepatitis C, Schistosomiasis
- Autoimmune diseases like systemic lupus erythematosus
- Genetic disease such as Autosomal dominant polycystic kidney disease (ADPKD)
Stages of kidney disease
- Stage 1 kidney disease
- Stage 2 kidney disease
- Stage 3 kidney disease which is either stage 3A or 3B kidney disease
- Stage 4 kidney disease
- Stage 5 kidney disease or kidney failure
General Signs and symptoms of kidney disease
- Body swelling which usually starts from the face around the eyes
- Fatigue-constantly feeling tired
- Itchiness of the skin
- Nausea and vomiting
- Abdominal pain
- Difficulty with breathing
- Cough with frothy sputum that may be pinkish to reddish in colour
- Foamy urine
- Blood in urine
- Reduction in amount of urine passed
- High blood pressure
- Reduced size of kidneys on ultrasound scan.
kidney disease stage 3 symptoms
The symptoms of chronic kidney disease stage 3 include:
- Urine that is coloured yellow, orange or red
- Change in urine frequency (more or less than normal)
- Anaemic-like symptoms
- Fluid retention (oedema)
- Inability to sleep.
- Lower back pain
- High blood pressure
Kidney disease tests
In the early phase of kidney failure that is the acute phase, your doctor would request for some tests for kidney disease such as blood tests, kidney function tests, blood counts and urinalysis. An abdominopelvic ultrasound scan may also be requested to see the structural abnormalities in the kidneys and urinary tract.
Treatment of kidney disease
Fluids and electrolytes are replaced if the cause of kidney failure is fluid volume depletion and electrolyte imbalances. This may be orally through the intake of oral rehydration therapy(ORT) or through intravenous fluids.
The harmful toxic substance is stopped immediately if it is the likely cause of the kidney injury and liberal intake of fluids (water) is encouraged. If the toxic substance is known, it may be neutralised with an antidote or removed by dialysis.
A catheter may need to be inserted in the urethra to drain urine and relieve the obstruction. In cases where there is a resistance to passing of urethral catheter, then a suprapubic catheter may be inserted through the lower abdomen into the urinary bladder.
Acute kidney failure is treated with urgency while monitoring kidney function with blood tests. If there are improvements with the aforementioned measures, then there might be no need for other medical procedures to improve renal function.
However, if the initial measures are ineffective in restoring renal function then the individual may need to be dialysed to restore kidney function. Usually after a few sessions, the kidney function may be restored. Unfortunately, in a subset of people, kidney function may not be restored after a few sessions of dialysis. They then become dialysis dependent and will need a more permanent renal replacement therapy.
What is renal replacement therapy?
It is any procedure that is carried out to perform the function of the kidneys in persons with kidney failure.
This may be either through haemodialysis or peritoneal dialysis- these are temporary renal replacement therapies. Renal transplantation is a permanent renal replacement therapy.
Kidney disease diet
Kidneys that are not working as they should means they cannot remove waste as it should. This causes waste and fluids to quickly build up. A kidney friendly diet is one where specific minerals and fluids are limited to prevent them from building up and causing problems. How much restriction required depends on the stage of your kidney disease.
- Try to avoid foods that are processed.
- Eat less saturated animal fats.
- To help with loss of appetite, eat smaller but frequent meals.
You may be asked to
- reduce the quantity of potassium-rich foods you take if your potassium levels become are too high,
- reduce the quantity of sodium-rich foods you take if your sodium levels become are too high,
- reduce your protein intake.
Visit kidney kitchen for kidney disease diets and kidney friendly food recipes.
Does kidney disease cause foamy urine?
Advanced kidney damage can make large amount of protein to leave the body through the urine. This can make your urine appear frothy or foamy.
Can kidney disease affect nails?
Yes advanced Kidney disease can affect the appearance of your nails (finger and toenails). The study evaluating Nail Disorders in Patients with Chronic Renal Failure in patient with end stage renal failure showed the presence of the following:
- Leukonychia (white spots)
- Brittle nails
- Half and half nails
- Nail clubbing
- Splinter haemorrhages (tiny blood spots underneath the nail)
- Longitudinal ridging
- Beau’s lines (deep grooved lines that run from one side of the nail to another)
- Melanonychia (black or brownish colouring of the nail plate)
- Onycholysis (detachment of the nail from the nail bed)
- Koilonychias (abnormally thin nails)
- Muehrcke lines(pattern of paired, white and transverse lines)
- Subungual hyperkeratosis (accumulation of scales under the nail plate)
- Paronychia (skin infection around the nail).
kidney disease with diabetes
Kidney disease is one of the complication of diabetes. Click the link to find out more.
Can kidney disease be reversed?
No, chronic kidney disease at any stage cannot be reversed. The goal of managing CKD at any stage to prevent further progression.
Can you get itching with kidney disease?
Yes as listed in the symptoms of kidney disease, you can get itching with kidney disease. This is referred to as uraemic pruritus and usually occurs in people with advance kidney disease or already having dialysis. The itching usually gets worse as kidney function worsens. You can read up more about itching with kidney disease here.
polycystic kidney disease
Click polycystic kidney disease to read more about it.