Lithiasis and Renal Colic

What is Renal Lithiasis?

Renal lithiasis refers to kidney stones which can cause renal colic due to their presence and movement.

The first stage of forming stones is the supersaturation of the constituent elements comprising the solid particles in the urine.  The presence of crystals or foreign bodies acts as a nucleus around which ions and microscopic crystalline structures cluster.

There are various types of stones, depending on their biochemical composition: 

  • Calcium stones account for around 80–85% of cases (the most common in Portugal are calcium oxylate, but others also exist: calcium phosphate and mixed oxylate and phosphate);
  • Uric acid stones (up to 10–15%);
  • Struvite stones or stones caused by infection (up to 10%);
  • Cystine stones (around 1%);
  • Other (less than 1%).

This urinary tract pathology is very common, and it is estimated that 9% of people may have renal lithiasis symptoms by the age of 45.

Risk Factors

The main risk factors are:

  • Low liquids consumption;
  • Low urination;
  • High concentrations of the component elements of stones;
  • Low magnesium and cytrate concentration (protecting against stone formation);
  • Use of certain drugs;
  • Family history;
  • Some glandular diseases, such as parathyroidism, or kidney diseases;
  • Obesity.

The formation of kidney stones is more prevalent in men than women with greater incidence in Caucasians than any other ethnicity.

Symptoms of Kidney Stones

Renal colic is usually described as one of the most painful events a person can experience. It is classically characterised as a very intense and sudden pain usually in the back or side that can radiate to the contralateral inguinal (“groin”) region. It is often accompanied by gastrointestinal symptoms, such as nausea and vomiting.

The association of fever with the above described symptoms is an important warning sign, as it indicates the possibility of one of the most dreaded complications of renal colic – infection. A patient with renal colic and fever must be seen immediately by a urologist.

When the stone is in the most distal point of the ureter or ureterovesicular junction, there may also be symptoms of lower urinary tract storage (higher urinary frequency, sudden urge to urinate and burning or discomfort when urinating).

Diagnosis of Renal Lithiasis

The presence of one or more obstructive ureteral stones causes classic renal colic (pain caused by obstruction).

Several complementary tests are necessary for a more precise assessment, such as:

  • Computed tomography
  • (CT scan);
  • Simple X-ray of the urinary tract;
  • Renal and vesical ultrasound;
  • Urinary sediment (presence of crystals and blood in the urine);
  •  Complete haemogram test and CRP (to assess if high inflammation parameters exist);
  • Biochemical blood test (particularly for urea, creatinine and ionogram to assess kidney function).



There are many diseases that can cause similar symptoms to renal colic and that should be considered in the differential diagnosis:

  • Genitourinary: lower urinary infection, pyelonephritis, tumours, clot obstructions, renal papillary necrosis, testicular torsion and other acute scrotal disorders, among others;
  • Gastrointestinal: appendicitis, bilious colic, cholecystitis, obstipation, intestinal occlusion, diverticulitis, gastric or duodenal ulcer, acute gastritis, perforated ulcer, inflammatory bowel disease, acute pancreatitis, abdominal abscess, among others;
  • Vascular: dissected and ruptured aortic aneurysm, renal infarction, renal vein thrombosis, splenic infarction and aortic aneurysm, and myocardial infarction;
  • Gynecological/obstetric: twisted ovarian cyst, salpingitis (inflammation of the fallopian tubes), pelvic inflammatory disease, ectopic pregnancy;
  • Neurological: sciatica, neuralgia, among others;
  • Osteoarticular or muscular: lumbago;
  • Other: such as the extrinsic compression of the ureter by a tumour or the lymph nodes, for example.

Do you Have Any of these Kidney Stone Symptoms?

If you think you might have renal colic or are suffering from renal lithiasis, book an appointment at the Instituto da Próstata.

Lithiasis and Renal Colic Treatment

After diagnosing renal colic, it must be ascertained whether an obstruction and/or infection exists so that suitable measures can be taken.

In the acute and intensely painful stage, the immediate aim is to relieve the pain. Evidence of complications must be sought, such as infection, bilateral obstruction or a single functioning kidney, or the presence of pus in the urinary tract. These are grounds for urgent/emergency surgery.

It cannot be over-emphasised that urgent surgery can save lives if there is evidence of obstruction and infection. Other criteria for surgery at this stage are vomiting, fever or general physical decline. If the pain continues or the stone is not eliminated after around 2 weeks, urgent surgery is also necessary.

After treatment of this acute stage, the main aim is to eliminate the stone causing the pain and, afterwards, to avoid the formation or growth of new ones.

The stone may be dissolved by alkalinising the urine. The alkalinisation of the urine is effective at dissolving uric acid stones even when they are large, provided patients stick to the treatment. In other types of stones, this treatment is not as effective and may even be dangerous (alkalinisation of the urine may cause infection).

Many patients try alternative treatments (with teas or other products – like the classic “quebra-piedras” bought in pharmacies, health shops or ordered from Spain).

The definitive treatment for stones involves lithotripsy (fragmentation). This can be external – extracorporal shockwave lithotripsy (ESWL) – or internal, via endoscopy and laser technology to fragment and eliminate the stones (ureterorenoscopy or retrograde intrarenal surgery with intracorporeal lithotripsy).

Renal Lithiasis Prognosis

Currently, the availability of minimally invasive surgical procedures has considerably increased the rate of success.

The rate of recurrence of kidney stones is 50% after 5 years and 70% after 10.

Ascertaining the composition of the stone, correctly assessing the metabolic risk and the patient’s close following of the treatment can significantly reduce the recurrence of lithiasis in most patients.

Dr. José Santos Dias

Clinical Director of the Instituto da Próstata

  • Bacherlor's Degree from the Faculty of Medicine at the University of Lisbon
  • Specialist in Urology
  • Fellow of the European Board of Urology
  • Autor dos livros "Tudo o que sempre quis saber Sobre Próstata", "Urologia fundamental na Prática Clínica", "Urologia em 10 minutos","Casos Clínicos de Urologia" e "Protocolos de Urgência em Urologia"

FAQs about Renal Lithiasis and Colic

How can urinary lithiasis be avoided?

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What are the symptoms of renal lithiasis?

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What are the risk factors for the formation of kidney stones?

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What treatments exist for renal lithiasis?

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Even after eliminating the stone causing the pain, can a new one occur?

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