Kidney (urinary) stones: what are the causes and symptoms?

The presence of kidney stones is a common disease of the urinary system. The cause of the formation of urinary concrements is multifactorial: from genetic predisposition, inappropriate lifestyle to various metabolic or urological diseases.

Symptoms, causes, diagnostic procedure, treatment options and many other interesting information can be found in the article.

What is urolithiasis?

Urolithiasis is a condition where urinary stones are present in the urinary tract. It occurs in approximately 10% of the population. The disease usually affects middle-aged individuals. It affects men more often.

The incidence of the disease increases with age. It decreases again in the elderly.

Recurrence of kidney stones is relatively common.

Urinary stones can occur in different parts of the excretory system.

According to the localization of concrements, urolithiasis is divided into :

• Nephrolithiasis (area of the kidney - pelvis)
• Ureterolithiasis(area of the ureter)
• Cystolithiasis (bladder area)
• Ureterolithiasis (urethral area)

The main function of the kidneys is to filter blood and produce urine. This is how the body gets rid of waste, unnecessary and harmful substances. The kidneys also regulate the absorption of water from the urine.

Stone-forming substances in high concentrations (minerals, salts), a small volume of urine or urinary sediment combine to cause the formation of urinary stones.

Initially, so-called crystals form. As they grow and clump together, they gradually turn into urinary stones (concretions).

According to the exact type, urinary concrements are divided into:

• calcium stones (approximately 70-80 % of cases)
• uric acid stones (5-10 %)
• struvite stones (5-15 %)
• cystine stones (1 %)

Urinary concrements are not a disease in themselves. They are a consequence of metabolic disease and morphological and functional changes in the excretory system. Untreated urolithiasis carries health complications and risks.

The characteristic symptom of kidney stones is renal colic. It is manifested by flushing pain in the lower back, which may spread to the groin.

In most cases of urolithiasis, multiple risk factors are identified. The etiology of the occurrence is multifactorial.

The most common causes of urinary stones are metabolic disorders and local changes in the urinary tract. Inappropriate diet and lifestyle play a significant role in the development of urolithiasis.

Causes of crystallization and stone formation :

• Excessive concentration of stone-forming substances in the urine. This may be due to metabolic disorders, excessive intake of stone-forming substances in the diet or drug therapy (drugs and medications).
• Urinary tract infections and subsequent changes in urine pH.
• Lack of inhibitors to prevent crystallisation and concretion formation (magnesium).
• Urinary tract obstruction: obstruction of the proper outflow of urine, presence of a foreign body and subsequent accumulation of urine.

What are the risk factors?

Risk factors for crystallization and stone formation...

Metabolic factor

Nutrition and diet significantly affect the function and condition of the excretory system. Excess animal protein and purines in the diet can lead to increased excretion of calcium, oxalate and uric acid in the urine. This results in a decrease in the pH level of the urine.

Disorders and diseases of the gastrointestinal tract can lead to excessive excretion of lithogenic (stone-forming) substances and a lack of inhibitors of crystallization and urinary acidification. Examples include malabsorption syndrome or chronic diarrhea.

Drug treatment is also a metabolic factor. Drugs may be part of the concretion or may induce the development of urolithiasis (e.g. acetazolamide).

Local urological factor

Local factors include disorders and diseases of the excretory system. Severe infections, frequent urinary tract infections, kidney disease, obstructive disorders with inadequate urine outflow, urinary congestion (pooling), abnormalities of the excretory system, and others.

Other risk factors

Genetic predisposition and positive family history are risk factors.

The period of pregnancy can trigger a slowing of urinary passage in a woman due to hormonal changes. There is also disharmony in calcium metabolism due to lactation and breastfeeding.

Another factor is the mode of labor. Long-term sedentary employment may play a role in the development of urinary concretions.

Climate also plays a role. Dehydration occurs more easily in hot and dry environments. Excessive exposure to sunlight leads to higher vitamin D production and calcium absorption.

Exposure to cold and hypothermia is also inappropriate.

Summary of possible causes of urolithiasis :

• Metabolic diseases
• Gastrointestinal disorders
• Urinary tract infections
• Frequent urinary tract infections
• Urinary tract obstruction
• Diseases of the excretory system
• Inappropriate diet
• Inappropriate drinking regime
• Small volume and accumulation of urine
• Adverse effect of pharmacological treatment
• Genetic influence and family history
• Pregnancy and breastfeeding in a woman
• Sedentary occupation, immobilization

The main clinical signs include colicky kidney pain in the lower back, kidney pain on palpation, nausea and difficulty urinating.

Possible symptoms of urolithiasis :

• Pain in the lower back
• Pain in the lower abdomen and groin, radiating to the testicles (scrotum)
• Pain in the kidney area
• Pain in the lower ribs
• Nausea
• Sensation of retching and vomiting
• Pain on urination
• Frequent urge to urinate
• Frequent frequency of urination
• Small volume of urine
• Smelly urine
• Cloudy urine
• Unusually coloured urine (pink, red, brown)
• Presence of blood in the urine
• Increased body temperature
• Fever and chills

In case of problems with urinary excretion, pain, fever and other atypical symptoms, it is necessary to seek professional help from a urologist.

If you notice blood in your urine, seek medical attention immediately.

The diagnostic process initially consists of taking a comprehensive history of the patient, assessing clinical symptoms and a palpation examination by a urologist.

Basic investigations include the collection and laboratory evaluation of the patient's urine sample. The urine is examined for the presence of crystals, blood and white blood cells. An examination of the type of urinary stone present may be added.

Usually a blood sample is taken to determine calcium, phosphorus, uric acid and creatinine levels.

Diagnostic imaging in the form of ultrasonography of the kidneys and bladder, X-ray, CT (computed tomography) or MRI(magnetic resonance imaging) are part of the diagnosis.

The choice of method depends on the examining physician. Ultrasonography is the preferred method. X-ray examination of the excretory system is one of the basic instrumental examinations, as up to 80% of urinary concrements are X-ray contrast.

The examination is used to accurately locate and determine the number and size of urinary stones.

Prevention of kidney stones

Prevention of kidney stones is based primarily on lifestyle, appropriate diet and environmental modification.

Some internal factors cannot be directly influenced. These include, for example, metabolic diseases or genetic predispositions. Rather, external factors such as diet, drinking, physical activity and stress can be influenced.

The basis of prevention is sufficient drinking during the day. The recommended amount is approximately 2 litres per day. A simple check is the feeling of thirst and cloudy urine. Excreted urine should have a light yellow clear colour.

Plain water, mineral water, herbal tea and fresh fruit/vegetable juices are suitable. A drink made from cranberries or blackcurrants is suitable for urological problems. Lemon water and apple cider vinegar are also suitable.

Excessive intake of highly mineralised waters with a high sodium content and carbonated drinks is inappropriate. A lower intake of coffee and cola drinks is recommended.

Alcohol should be avoided. However, beer and wine have several advantages. These include the flavonoid content of wine and the diuretic effect of beer.

It is advisable to follow the recommended daily intake of calcium, potassium and magnesium. One mistake is to reduce calcium intake in the diet. Conversely, a diet high in calcium reduces the risk of kidney stones.

It is advisable to follow a balanced regular diet with plenty of vegetables, fruit and fibre.

Cranberries benefit the excretory system. They contain phytonutrients called proanthocyanidins type A, which prevent the spread of bacteria and inflammation in the urinary tract.

Good vegetables include parsley, broccoli, celery, asparagus, garlic, onions, horseradish and radishes.

It is necessary to limit salt and animal protein intake. Animal protein is a rich source of purines. Purines break down into uric acid in the body and may increase the risk of kidney stones.

It is recommended to limit sodium and added salt. Garlic is therefore a good choice. It adds flavour to food and has anti-inflammatory effects.

Herbal teas and extracts in dietary supplements will provide natural support. For example, rose hips, dandelion, cranberries, nettle, horsetail, anchovy and others support urinary tract function. In most cases, they have a diuretic effect.

Regular physical activity and compensation for sedentary work is advisable. It will help blood circulation of the area and elimination of the action of cold.

The basics of prevention of urinary stones :

• Adequate drinking and urination
• Adequate intake of vegetables, fruit and fibre
• Adequate intake of vitamins and minerals
• Elimination of sodium and salt intake in the diet
• Elimination of animal proteins and purines in the diet
• Elimination of stress
• Regular physical activity
• Elimination and compensation of sedentary work
• Elimination of exposure of the urinary tract area to cold
• Adequate hygiene and prevention of infection