Renal colic

Renal colic is caused by a blockage of the urinary tract.

The urinary tract apparatus includes the kidneys, ureters, bladder and urethra.
The ureters carry urine from the kidneys to the bladder.
The urethra carries urine out of the body during urination.
The most common causes of urinary obstruction are kidney stones, which can form in both kidneys and ureters.
Also, blood clots, muscle spasms of the ureter and dead tissue can block the urinary tract.

Kidney limestones are most common in men between 30 and 50 years of age.


What are the causes of renal colic?

Renal colic is caused by the accumulation of kidney stones. If these stones interfere with the flow of urine, they can cause swelling and very severe kidney pain (colic).
Kidney stones can also occur in children, although this is very rare.

Causes of
kidney stones

Kidney stones that cause renal colic consist of a variety of chemical products and may be due to:

  • Chemotherapy
  • Cystinuria (hereditary disease characterized by an increased amount of cystine in the urine)
  • Small bowel disease
  • Gout (type of arthritis caused by accumulation of uric acid in the joints)
  • Hypercalciuria (increased amount of calcium in the urine)
  • Hyperuricosuria (increased amount of uric acid in the urine)
  • Inflammatory bowel disease (Crohn’s disease and ulcerative colitis)
  • Kidney disease
  • Surgery
  • Urinary tract infections

What are the risk factors for renal colic?

There are numerous factors that increase the risk of renal colic.
Not all people with risk factors develop renal colic.
Risk factors include:

  • Dehydration
  • Sport (causes severe fluid loss)
  • Diet high in vitamin D
  • Family predisposition to kidney stones
  • Personal history of kidney stones
  • Urinary tract infection
  • Use of calcareous antacids
  • Use of certain medications

How to prevent renal colic?

To reduce the risk of developing kidney stones and renal colic, one should:

  • abstain from calcium supplements;
  • avoid some foods high in oxalate, such as rhubarb and spinach;
  • restrict the consumption of meat, fish and poultry;
  • Drink plenty of fluids, especially water, to prevent dehydration.

What are the symptoms of renal colic?

Symptoms of renal colic can occur daily or rarely.
Some of these symptoms can be severe:

  • Unnatural coloring of urine;
  • fever with or without chills;
  • bad urinary odor;
  • nausea with or without vomiting;
  • pain in the right or left flank, back, abdomen or groin;
  • colic usually begins at night, but it can also occur in the morning or afternoon.

Intensität der Nierenkolik
Nierenkoliken sind sehr ernst und meist verspüren Menschen mit Nierensteinen ohne Ankündigung einen plötzlichen starken Schmerz.
Die Intensität kann schlimmer sein, als die Schmerzen bei einer Geburt, einem Knochenbruch oder einer Operation.

Lage und Eigenschaften der durch Nierensteine verursachten Schmerzen
Nierensteine entstehen hauptsächlich in den Nieren und bewegen sich entlang des Harnleiters nach unten. Auf ihrem Weg können sie Harnleiter und Becken oder Blase passieren.
Wenn sie sich im Harnleiter festsetzen, können starke Flankenschmerzen auftreten, die bis in den Unterbauch, die Hoden oder die Vulva ausstrahlen.
Dabei können auch Übelkeit und Erbrechen auftreten.

Symptoms that may
indicate a serious illness 
In some cases, renal colic is a serious condition that should be viewed immediately by a doctor.
You should seek immediate medical help in the following cases:

  • High fever (above 38°C)
  • Inability to urinate
  • Uncontrollable vomiting

Renal colic in pregnancy
Renal colic can also occur in pregnant women due to hydronephrosis or kidney stones.
Hydronephrosis is a condition that causes swelling of the kidney because the urine cannot be drained.
It is often asymptomatic, but can also cause severe pain in some cases.

Diagnosis of renal colic

The doctor must examine the patient to determine the cause of the symptoms. In addition, he must exclude other diseases with similar symptoms, such as cystitis or appendicitis.
Diagnosis of renal colic is carried out with the help of:

  • Blood tests to check kidney function or detect infection.
  • Urine test to check kidney function.
  • X-rays, ultrasounds, CT or NMR can reveal kidney stones or other causes of pain.

Therapy of renal colic

If a patient feels severe pain, he usually goes to the emergency room immediately.
In an acute phase, the doctor usually recommends rest, drinking water and possibly painkillers.
The therapy of colic and kidney stones provides for the relief of pain and the destruction of kidney stones. In some cases, the kidney stones and the associated symptoms disappear on their own.
However, recurrences in kidney stones are common. Drinking plenty of fluids can aid recovery and relieve the pain of renal colic.

Medication for colic and kidney stones
Most often, in the acute phase, the doctor recommends nonsteroidal anti-inflammatory drugs such as diclofenac (Diclo, Voltaren®).
Antispasmodics such as butylscopolamine (Buscopan®) are not indicated at this stage because muscle spasms are not the causes of symptoms.

After the first few hours, the doctor may prescribe some medications to destroy the kidney stones and relieve the pain.
Drugs for renal colic include:

  • Allopurinol (against uric acid kidney stones).
  • Alpha-blockers for eliminating kidney stones.
  • Antibiotics to fight infections.
  • Cystine control drugs that lower the amount of this amino acid in the urine.
  • Painkillers and antipyretics (to lower fever), for example, paracetamol.
  • Potassium citrate or sodium bicarbonate to regulate urine pH and prevent the formation of kidney stones.

Other treatments for colic and kidney stones
In addition to medication, other forms of treatment may be needed for the healing or removal of kidney stones.
In some cases, it is necessary to resort to surgery.
Treatment options for kidney stones include:

  • Lithotripsy (use of ultrasound to destroy the kidney stones).
  • Surgery to remove large kidney stones.
  • Use of a ureter stent to keep the urinary tract between the kidneys and bladder (ureter) open.
  • Ureteroscopy (minimally invasive surgery).

After a few hours, patients with renal colic can already experience significant relief when the kidney stones in the bladder shift and pass through the urethra. If the patient is still under medical supervision, urine can be filtered through a sieve to confirm successful excretion of the kidney stone.

How long do colic last? How long does recovery take?

With proper therapy, treatment lasts a few hours.

Natural remedies for renal colic

In the acute period, natural remedies are not effective. For some people, a hot water bottle can provide relief.

What to eat? Diet and nutrition for renal colic

Calcium kidney stones
Limit foods high in oxalate. Some foods contain a lot of oxalates, such as:

  • Spinach
  • Rhubarb
  • Courgette
  • Asparagus
  • Nuts
  • Wheat bran.

Consumption of these foods causes excessive excretion of oxalates in the urine, which combine with calcium and form calcium oxalate stones.
Increasing calcium levels can interact with oxalates and phosphates and lead to kidney stone formation.
Calcium from foods and dietary supplements binds oxalate in food. This compound does not enter the blood and urinary tract, thus preventing the formation of calcium oxalate kidney stones.

Supplements with vitamins C and D may increase the risk of kidney stones. Vitamin C or ascorbate can be converted into oxalate in the body.

Also, restricting sodium (salt) can help prevent kidney stones. The increase in sodium in the urine can cause increased calcium excretion.

One should avoid foods high in sodium, such as:

  • Hotdogs
  • canned soups and vegetables,
  • Processed foods and frozen foods,
  • Fast food.

By checking the labels, you can avoid food products that contain hidden sodium, such as:

  • monosodium glutamate (MNG),
  • disodium phosphate,
  • sodium alginate,
  • Sodium nitrate
  • Nitrite, etc.

Lemon juice or lemonade are excellent for lowering the pH in the urine and preventing the formation of kidney stones.
One should also include ginger in the diet.

Animal proteins should be restricted as they increase the excretion of calcium in the urine and reduce the excretion of citrates.

Uric acid kidney stones
Animal proteins contain purines, which decompose in uric acid and are excreted in the urine. Therefore, one should limit the consumption of animal proteins to prevent the formation of uric acid kidney stones.
Likewise, the consumption of milk, dairy products, poultry, eggs, fish, etc. should be avoided or severely restricted. Offal such as liver also contain a lot of purines. Maintaining a healthy body weight, an adequate diet and sufficient exercise reduce the occurrence of kidney stones and uric acid.

To prevent the formation of kidney stones, water intake should be increased (2 liters per day).

Further studies have shown that consuming orange juice and soda can increase the concentration of citrate in the urine and lower the pH, thereby reducing the risk of kidney stones.
As a precaution, it is preferable to drink orange juice instead of lemonade and blueberry juice, as it has a more alkalizing effect and is able to increase citrate excretion in the urine, with the result that the kidney stones dissolve more easily.

What water should you drink?
You should drink water with a low pH value and few solid residues.

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