Kidney infection: what are the symptoms of pyelonephritis and how is it treated?
Kidney infection or pyelonephritis is one of the urinary tract infections that affect 1 in 3 UK people during their lifetime. Most often the result of untreated or poorly treated cystitis, it can cause a great deal of inconvenience. How can you recognise a kidney infection? How can it be treated? We're here to help.
What are the symptoms of a kidney infection?
Pyelonephritis is a bacterial infection of the kidneys. It is most often caused by the Escherichia coli bacterium, which belongs to the enterobacteria family and normally develops in the intestine.
Symptoms of kidney infection include:
- pain in the kidney or back, on one side only
- a frequent urge to urinate (but sometimes difficulty in doing so)
- a burning sensation and pain when urinating
- nausea and/or vomiting
- fever (temperature above 38.5°C)
- chills
These symptoms are sometimes accompanied by digestive problems, an accelerated heart rate and the presence of blood in the urine or pus, causing unpleasant odours. All these symptoms are not always present; pyelonephritis without fever, for example, is rare.
In babies and young children, the symptoms of kidney infection include fever, weight loss, pain when urinating (manifested by crying), cloudy urine and stomach pains.
What causes pyelonephritis?
Pyelonephritis is often the result of cystitis that has not been treated properly or has resisted antibiotics. However, this is not the only cause of this infection.
Causes of kidney infection
Pyelonephritis can affect anyone, at any age. It can be contracted in a number of ways, but most often occurs as a result of cystitis that has been poorly treated or has resisted treatment. The bacteria then travel from the bladder via the urethra to the kidneys.
A kidney infection can also occur as a result of an obstruction of the urinary tract. This can be caused by a malformation of the urinary tract, a kidney stone, a tumour or an enlarged prostate, for example.
Kidney infection: why are women more affected?
Pyelonephritis is more common in women because their urethra is shorter. This makes it easier for bacteria on the vulva or perineum to travel up to the bladder, and even to the kidneys if the infection is not treated beforehand.
Pregnancy is a period that requires particular vigilance. Firstly, because the anatomical and hormonal changes that accompany it make it easier for bacteria to travel from the bladder to the kidneys, and secondly because infection increases the risk of premature delivery and can be passed on to the baby.
Pyelonephritis: what are the consequences if it is allowed to get worse?
It is important to treat a kidney infection as soon as the first signs appear, otherwise the consequences could be serious. If pyelonephritis is left untreated:
- the infection continues to develop;
- it can cause damage to the kidney;
- you may develop a renal or peri-renal abscess (affecting a surrounding organ);
- the infection can spread and develop into septicaemia, which can be fatal.
These complications can have a significant impact on health. In the event of symptoms suggestive of a kidney infection, it is best to consult a doctor as soon as possible for diagnosis and appropriate treatment. Serious cases are rare, however, and mainly affect the frail (elderly, immunocompromised, etc.).
How can a kidney infection be cured?
A kidney infection needs to be taken seriously and cannot be cured by natural treatments. To cure it, you need to be diagnosed by a doctor and given a course of antibiotics.
Diagnosis of pyelonephritis
Diagnosis of kidney infection requires tests prescribed by a doctor. Urine is analysed using a urine dipstick and a urine cytobacteriological examination (ECBU) is carried out. If there are risk factors or signs of seriousness, blood tests and/or imaging of the kidneys and urinary tract (ultrasound or CT scan) are also carried out. This is to detect any complications or obstructive causes.
Antibiotic therapy: the preferred treatment for pyelonephritis
As soon as infection is suspected, the doctor prescribes a course of antibiotics. This is then adjusted according to the results of the tests. It lasts from 7 to 10 days for simple, acute kidney infections, and can last up to 14 days in serious cases or cases where there is a risk of complications (the body's resistance to antibiotics, illnesses that weaken the immune system such as diabetes or cancer, prostatitis, kidney stones, etc.). Some cases may also require hospitalisation, particularly if the urinary tract is obstructed, in which case drainage is required.
How can kidney infections be prevented?
Although there is no such thing as a 0 risk, there are some simple things you can do to prevent pyelonephritis and urinary tract infections in general:
- drink 1.5 to 2 litres of water a day
- urinating after sex
- wipe from front to back when using the toilet
- avoid douching and scented intimate hygiene products
- wear cotton underwear
- be vigilant in the event of a prolonged urinary infection
- change babies' nappies regularly