Kidney disease often develops silently. Learn about their causes, symptoms and treatment

The kidneys are a pair of organs that are very important for the proper functioning of the human body and are located on both sides of the spine, in the lower back. An important function of the kidneys is to cleanse the blood of harmful metabolic by-products and other toxins (e.g. drug metabolites) and to produce urine, which flows down the ureters to the urinary bladder and is then removed from the body through the urethra. Kidney disorders cause serious problems in the functioning of the body, leading to, among others: to an increase in the level of harmful toxins.

Kidney diseases may develop asymptomatically or with few symptoms, which makes diagnosis difficult. It is worth remembering that a regularly performed general urine test allows you to monitor the health of your kidneys and detect abnormalities related to their functioning before typical symptoms of kidney disease appear, e.g. back pain, lower abdominal pain, frequent urination and other problems with urination, as well as indicating for serious kidney problems, urinary retention.

Kidney diseases – basic information

Kidney diseases lead to serious disorders in the functioning of the body. If this organ does not function properly, the following may occur:

• water and electrolyte balance disorders,

• acid-base balance disorders,

• hormonal disorders,

• hypertension,

• symptoms of body poisoning with harmful metabolic products.

Often, one of the first symptoms of kidney disease are problems with the urinary system and the lumbar-sacral spine. Depending on the cause of the disease and the degree of its advancement, the symptoms are mild, moderate or severe.

If left untreated, kidney diseases may lead to organ failure. One of the basic classifications divides kidney diseases into acute and chronic diseases.

The most frequently diagnosed kidney diseases include:

• kidney stones,

• nephritis (e.g. primary glomerulonephritis and secondary glomerulonephritis, interstitial nephritis, lupus nephritis, interstitial nephritis, pyelonephritis),

• single and multiple renal cysts,

• acute renal failure (acute kidney injury),

• chronic kidney failure (chronic kidney disease – CKD),

• kidney cancer.

Kidney stones – causes, symptoms, treatment

Kidney stones are a kidney disease that is more often diagnosed in men. Kidney stones cause the formation of deposits of various sizes in the kidneys (kidney stones), which include, among others: from calcium and uric acid. The disease develops asymptomatically – if the deposits in the kidneys obstruct the outflow of urine or start to move, characteristic symptoms of renal colic appear. The passing stones can damage the delicate structures of the urinary system, causing inflammation. In extreme cases, serious disorders in the functioning of the urinary system may occur, which are related to, for example, blockage of the ureter by renal deposits.

In most cases, renal colic goes away on its own once the deposits are expelled from the body through the urethra. Even small kidney stones that move through the urinary tract cause severe colic pain.

The causes of kidney stones include:

• a diet rich in animal protein, oxalates and salt,

• dehydration of the body, which leads to urine concentration,

• some chronic diseases, e.g. gout, urinary tract infection, hyperparathyroidism, defects in the anatomical structure of the kidneys, metabolic disorders,

• taking certain medications,

• genetic factors.

Symptoms of kidney stones include:

• sharp pain in the lower abdomen and lower back, which may radiate to the groin or thigh,

• burning or pain when urinating,

• urination disorders (e.g. frequent urination, urinary retention)

• nausea, vomiting,

• fever.

Treatment of kidney stones includes, among others: conservative treatment (drinking plenty of fluids, painkillers, anti-inflammatory drugs, antispasmodics, use of a properly composed diet, use of herbs and other preparations with a diuretic effect and cleansing the kidneys of deposits) and surgical treatment, which its aim is to remove an obstacle that hinders the outflow of urine (e.g. breaking up kidney stones with ultrasound).

Nephritis – causes, symptoms, treatment

Nephritis is a group of inflammatory kidney diseases, which include: inflammation of the glomeruli of the kidney (glomerulonephritis), inflammation of the kidney tubules (tubular nephritis) and inflammation of the glomeruli and kidney tubules (interstitial nephritis) .

Causes of nephritis these include: bacterial, viral and fungal infections and autoimmune diseases (e.g. systemic lupus erythematosus).

Nephritis may be acute or chronic. Acute diseases begin suddenly, their symptoms are severe, but most often they do not cause complications. In some cases, acute renal failure is diagnosed. Unfortunately, chronic nephritis is often asymptomatic and may lead to complete kidney failure.

Symptoms of nephritis include:

• pain in the lumbar-sacral spine and lower abdominal pain of low or moderate intensity,

• fever or recurrent low-grade fever,

• hematuria,

• proteinuria,

• swelling,

• hypertension,

• urinary disturbances.

Kidney inflammation can be detected by regular preventive tests (general urine test, blood count with smear, kidney ultrasound).

Treatment for nephritis depends on the cause and type of inflammation and the degree of kidney damage. It may include antibacterial, antiviral or antifungal drugs, anti-inflammatory drugs, immunosuppressants, drugs to lower blood pressure, or renal replacement therapy.

Acute renal failure (acute kidney injury) – causes, symptoms, treatment

Acute renal failure, also known as acute kidney injury, is a sudden impairment of kidney function accompanied by an increase in blood creatinine concentration and a decrease in the volume of urine excreted below 500 ml per day.

The most common causes of acute kidney failure are:

• decreased renal blood flow, which may be associated with e.g. hemorrhage, dehydration, heart failure, shock;

• damage to the renal parenchyma, which is most often caused by renal ischemia and may be a complication of nephritis;

• obstruction of urine outflow from the kidneys, which is related to obstruction caused by a urinary stone or tumor, as well as compression of other organs in which e.g. cancerous tumors develop.

Other causes of acute kidney failure include: complications of untreated or incorrectly treated inflammatory diseases of the kidneys, hemolytic uremic syndrome, thrombotic thrombocytopenic purpura, use of certain drugs, toxic kidney damage, e.g. by alcohol.

Symptoms of acute renal failure are related to the underlying cause of the disease. These include:

• symptoms of nephritis,

• symptoms of renal colic,

• symptoms related to medical conditions that have reduced renal blood flow, e.g. heart failure-related arrhythmias,

• oliguria,

• anuria,

• hematuria.

Treatment of acute renal failure involves treatment of the underlying disease and symptomatic treatment, which aims to reduce troublesome symptoms.

Chronic kidney disease (CKD) – causes, symptoms, treatment

Chronic kidney disease gradually damages the kidney parenchyma. As the disease progresses, kidney problems become more severe. Chronic kidney disease leads to irreversible damage to the kidneys. If the kidneys cease to function, the patient qualifies for renal replacement therapy. The hope for recovery is a kidney transplant. Kidney transplantation is possible from both a related and unrelated donor.

The most common causes of CKD include:

• diabetic kidney disease (diabetic nephropathy),

• glomerulonephritis,

• interstitial nephritis,

• complications of kidney stones,

• hypertension (hypertensive nephropathy),

• atherosclerosis,

• kidney cancer,

• congenital kidney defects.

CKD symptoms are related to disorders of water and electrolyte balance, acid-base balance, hormone production and toxin excretion. These symptoms may be non-specific and appear gradually. The most common symptoms of chronic kidney disease include:

• proteinuria, hematuria and urination disorders;

• swelling of the face and lower limbs, which is related to fluid retention in the body;

• arterial hypertension, which is related to impaired regulation of pressure by the kidneys;

• weakness, fatigue, drowsiness, which are related to the accumulation of toxins in the blood;

• nausea, vomiting, diarrhea, which are related to acid-base disturbances;

• anemia, which is associated with a deficiency of erythropoietin produced by the kidneys;

• bone and muscle pain, which is related to calcium-phosphate metabolism disorders and vitamin D deficiency;

• itching of the skin, which is related to the accumulation of metabolic products in the body.

Diagnosis of CKD involves assessing renal excretory function, which includes performing various tests (e.g. general urinalysis, glomerular filtration rate GFR).

Treatment of CKD includes causal treatment, conservative treatment and supportive treatment that helps slow the progression of the disease. Causal treatment may include pharmacological treatment (e.g. antidiabetic drugs, blood pressure drugs, immunosuppressive drugs), surgical treatment (e.g. removal of kidney stones, correction of urinary tract defects) and renal replacement therapy (dialysis or kidney transplant).

Preventive and supportive treatment of chronic kidney disease includes, among others:

• following a low-protein diet and limiting salt intake,

• avoiding smoking, drinking alcohol and taking certain medications (e.g. non-steroidal anti-inflammatory drugs)

• taking medications that improve kidney function,

• the use of drugs that alleviate the symptoms and complications of CKD.

During the treatment stage, it is necessary to constantly monitor high blood pressure, glucose levels, cholesterol and triglycerides. Patients should have regular urinalysis and imaging tests performed.

Sources:

• Michał Myśliwiec, Wielka Internal Medicine Nephrology – 2nd edition, Medical Tribune Polska Publishing House, 2017

• Michał Myśliwiec, Kidney diseases, PZWL Medical Publishing House. Warsaw, 2008

• Andrzej Więcek, Teresa Nieszporek, Kidney diseases. Compendium, PZWL Medical Publishing House. Warsaw, 2019