Kidney and Ureter Stones

 

 

Overview

Stones are a common problem of the renal tract and they can form in the kidney and the ureter (tube between the kidney and the bladder). Often stones form when the urine is concentrated, encouraging minerals to form crystals, which then stick together to form stones.

 

About 3 in 20 men and 1 in 20 women develop kidney stones in UK at some stage in their lives. Kidney stones can occur at any age, but most commonly affect people between the ages of 20 and 40 years. Approximately, one in five patients with a kidney stone will have another stone within 5 years. 

 

Kidney stones often have no definite single cause; although, several risk factors may contribute to the formation of a stone.

 

Kidney stones form when the urine contains more crystal-forming substances (like calcium and oxalate) than the water in the urine can dilute. In addition, the urine may lack substances that keep the crystals from sticking together like citrate.

 

We may have a better understanding of the causes of the stone by knowing its type, which will perhaps help us preventing the formation of further stones in the future.

 

 

Types of kidney stones:

  • Calcium stones: these are the most common type of kidney stones and are usually combined with oxalate forming calcium oxalate stones. Sometimes they occur in the form of calcium phosphate.

 

  • Struvite stones: these stones are often caused by urinary tract infections and are more common in women. They can grow quickly and become quite large.

 

  • Uric acid stones: often form when the urine is more acidic than what it should be or less commonly when there are high levels of acid in the urine. They may be seen in those who eat high protein in the diet, gout patients and in certain genetic disorders.

 

  • Cystine stones: these are a rare type and are caused by an inherited condition called cystinuria.

 

 

Risk factors for kidney stones:

  • Gender: men are more commonly affected than women until the age of 50, when the sex distribution becomes equal.

 

  • Age: kidney stones are most common between 20 and 40, although they may occur at any age.

 

  • Dehydration: not drinking enough fluids is one of the most important risk factors.

 

  • Diet: eating food that is rich in protein, salt, sugar and oxalate may increase the risk of developing stones.

 

  • Previous personal or family history of kidney stones: the risk for forming stones increases with positive history.

 

  • Obesity: the risk increases in those with high body mass index (BMI), large waist size and metabolic syndrome.

 

  • Certain medical conditions: such as inflammatory bowel disease (Crohn's disease), chronic diarrhoea, previous bowel surgery, gout, hyperparathyroidism, renal tubular acidosis, cystinuria, urinary tract infections, medullary sponge kidney and nephrocalcinosis.

 

  • Certain medicines: this is uncommon including calcium and vitamin D supplements, certain diuretics, chemotherapy and drugs to treat HIV. Please do not stop any medicine if you think it is causing your kidney stones, but consult your GP first.

 

  • Anatomical risk factors: certain anomalies in the renal tract such as horseshoe kidney, PUJ Obstruction, ureteric stricture and calyceal diverticulum can increase the risk of forming stones.

 

 

What are the symptoms of kidney stones?

  • No symptoms: sometimes kidney stones do not cause any symptom and are discovered by chance when you are having a scan for another reason.

 

  • Loin pain: kidney stones may cause pain in the side of the abdomen.

 

  • Renal colic: if a stone becomes stuck while passing through the ureter (the tube between the kidney and the bladder), it can cause a distressing side pain that tends to come and go. The pain may spread down to the lower abdomen and often there is nausea (feeling sick) and sweating.

 

  • Blood in the urine (haematuria).

 

  • Infection: urinary tract infections are more common in people with kidney stones and can lead to pain, high temperature, burning when passing urine and needing to urinate more frequently.

Diagnosis of kidney stones

This includes a full history, physical examination and additional tests including:

  • Blood tests to assess the kidney function, calcium and uric acid levels.

 

  • Urine test to rule out infection.

 

  • CT scan to confirm the diagnosis and determine the size, number and location of the stone(s).

 

  • Stone analysis: a stone (either if passed spontaneously or when removed by surgery) is sent for analysis to determine the type.

 

  • 24 hours urine collection and test is done in selected cases to look for the causes of the stone.

     

     

Treatment of kidney stones

 

Emergency treatment:

If you have a renal colic then the first step is that you will be given strong pain killers to relief the pain. Further treatment will depend on many factors including your wellbeing, symptoms, renal function, size and location of the stone and presence of urinary tract infection. Treatment options include:

 

 

  • Medical expulsive therapy. This involves giving you pain killers and medications to help you pass the stone on your own. Passing a stone is not usually painful, and sometime happens without knowing. Therefore, you will be asked to urinate in a clear container every time you pass urine to look for the stone. The stone usually sinks to the bottom of the container. If you pass the stone then keep it and bring it back to the hospital so that it can be send for analysis. If you fail to pass the stone then you will be offered one of the definitive treatments (see below).

 

  • Insertion of a temporary ureteric stent or a nephrostomy tube to relief kidney obstruction. This is done particularly when the stone is blocking the ureter and at the same time causing severe urinary tract infection.

     

Definitive treatment of the stone:

There are a number of definitive treatment options depending on the stone (in terms of size, location and type), your general health and preference. These options will be discussed with you and they include:

 

 

 

 

  • Medications to dissolve the stone may be used in specific types of stone such as uric acid and cystine stones.

     

     

Prevention of kidney stones

The risk of forming another stone might be reduced with life style changes and possibly medications:

 

Life style changes:

  • Drink plenty of water. This is the most important factor for prevention of further stones. The exact amount of water you need to drink daily is variable, and the best indicator is the colour of your urine; dark yellow urine indicates dehydration and inadequate fluid intake. Therefore, you should aim to keep the colour of the urine as light as possible most of the time. Remember you need to drink more during hot days or when exercising.

 

  • Minimise your salt and sugar intake.

 

  • Reduce the intake of animal protein (meat, poultry and fish).

 

  • Eat less oxalate-rich diet. If you have calcium oxalate stone, then restrict the intake of food rich in oxalates. These include rhubarb, tea, spinach, strawberries, nuts, chocolates and sweet potatoes.

 

  • Do not reduce calcium intake. Calcium in food does not have an effect on the formation of kidney stones. It is important that you continue eating calcium-rich food, such as milk and cheese, as normal. In fact, reducing calcium in your diet may increase the risk of forming kidney stones. However, avoid taking any calcium supplements.

 

  • Eat more fruit and vegetables.

 

  • Citric acid helps to reduce formation of stones. The best source of citric acid is lemon or lime. Therefore, you are encouraged to drink a glass of freshly squeezed lemon juice or lemonade regularly. Please avoid any sugar in the drink as sugar increases the risk of stone formation.

     

Medications:

Occasionally, patients with kidney stones are found to have a high level of minerals or acid in the urine. In these situations, medications may help to control the level of these minerals or acid in the urine, reducing the risk of forming further stones.  

Send Us a Message

Private Secretary Contact

Debbie Coleman

KIMS Hospital

Newnham Court Way

Maidstone

Kent

ME14 5FT

Tel: 01622 538173

email: debbie.coleman@kims.org.uk

Links

© East Sussex Urologist.