Inflammation of renal pelvis: symptoms, causes, therapy

Inflammation of renal pelvis: symptoms, causes, therapy

inflammation of renal pelvis, Inflammation of renal pelvis: symptoms, causes, therapy

Inflammation of  renal pelvis (pyelonephritis, PN) is a mostly bacterial infection of the renal pelvis. This is the funnel-shaped cavity in the kidneys where urine collects before it continues to enter the bladder via the ureter. Inflammation of the renal pelvis is usually the result of an ascending infection: the pathogens migrate up the urethra, bladder and ureter to the renal pelvis. Women are more frequently affected than men because of their relatively short urethra. Read here how to recognise inflammation of the renal pelvis and how to treat it.

Brief overview

  • What is inflammation of the renal pelvis? An infection of the upper urinary tract (usually caused by bacteria) and one of the most common kidney diseases.
  • Symptoms: For acute inflammation of the renal pelvis fever, chills, flank pain and nausea. In the case of chronic inflammation of the renal pelvis, headaches, fatigue, back pain and loss of appetite; in relapses, similar symptoms as in acute forms.
  • Causes: usually bacteria, more rarely other pathogens (such as fungi); risk factors: Urinary flow disorders, infections of the urinary tract, pregnancy, metabolic diseases etc.
  • Diagnosis: Taking a medical history during a conversation (anamnesis), physical examination, blood test (CRP. sedimentation rate etc.), urine test (creatinine, leucocytes etc.), if necessary imaging procedures (ultrasound, computer tomography)
  • Treatment: antibiotics, possibly antipyretics; treatment of risk factors (e.g. surgery for urinary flow problems due to an enlarged prostate)
  • Prognosis: With timely treatment, the acute form usually heals well. The prognosis of the chronic disease is less favourable. Untreated, inflammation of the renal pelvis can cause serious complications (kidney failure, blood poisoning).
  • Prevention: sufficient drinking, regular urination, appropriate intimate hygiene (not too much and not too little), etc.

Inflammation of renal pelvis: Symptoms

The inflammation of the renal pelvis (pyelonephritis) can be acute or chronic. Usually only one kidney is affected by the inflammation.

Acute inflammation of renal pelvis: Symptoms

Acute inflammation of the renal pelvis usually causes sudden and severe symptoms. These include:

  • high fever (around 40 °C), often combined with chills
  • severe flank pain (lateral back pain in the area of the affected kidney); the pain can radiate into the pelvis
  • Nausea and vomiting
  • during palpation strongly tense muscles (immune system tension) in the transition area from the ribs to the spine
  • frequent urination, always with only small amounts of urine passing out (pollakiuria); emptying the bladder is painful (dysuria)
  • sometimes blood in urine

Note: In the absence of clear symptoms such as flank pain and high fever, this is called atypical pyelonephritis.

Children and elderly people in particular can show symptoms of inflammation of the renal pelvis that are initially difficult to assign to the disease – for example headaches, abdominal pain, nausea and slight fever.

In patients with pre-existing conditions such as diabetes mellitus (diabetes) and infections with so-called “hospital germs”, strong signs of inflammation often occur during the course of the disease, affecting the entire body. Sometimes an acute inflammation of the renal pelvis can lead to a renal abscess (encapsulated accumulation of pus), or pus can collect in the cavities of the kidney (pyonephrosis). Doctors then speak of a complicated pyelonephritis.

Chronic inflammation of renal pelvis: symptoms

If an acute inflammation of the renal pelvis remains untreated, it can develop into a chronic inflammation of the renal pelvis. This form damages the kidney slowly and continuously, the tissue scars over years. In most cases, no symptoms at all (“silent” course) appear for a long time. At some point, however, chronic inflammation of the renal pelvis may cause symptoms, but these are not very specific:

  • Headache
  • Tiredness and exhaustion
  • dull back pain in the lumbar region
  • Loss of appetite
  • Stomach pain, possibly nausea
  • Problems with urination
  • Weight loss

Normally, chronic inflammation of the renal pelvis occurs without fever (at most slightly elevated body temperature). However, there can always be an occasional relapse. These are accompanied by fever and other symptoms, such as those that occur in acute inflammation of the renal pelvis.

Since the kidneys are involved in blood formation, chronic inflammation of the renal pelvis can lead to anaemia. Because the diseased kidney excretes less fluid, high blood pressure can also develop.

Due to the chronic inflammatory processes, functional kidney tissue is gradually transformed into non-functional scar tissue. The affected kidney is therefore increasingly unable to do its job – kidney weakness (renal insufficiency) can develop into chronic kidney failure.

Pelvic inflammatory disease: Treatment

Acute pyelonephritis is mostly caused by bacteria. It is therefore primarily treated with antibiotics: The patient must take these over seven to ten days. Initially, he is given a broad-spectrum antibiotic that is effective against numerous different bacteria. As soon as the result of the urine examination is available (i.e. the exact type of pathogen is identified), the doctor can switch treatment to an antibiotic that specifically helps against the germ in question.

Note: A severe inflammation of the renal pelvis is usually treated in hospital. If the patient suffers from nausea and vomiting, the antibiotics are often administered intravenously, i.e. via an infusion.

In addition to antibiotics, the doctor may prescribe antipyretics to reduce fever in the case of inflammation of the renal pelvis. Patients should also stay in bed and drink a lot during treatment (at least two to three litres). The latter helps to flush the bacteria out of the kidneys and urinary tract.

Antibiotics are also used to treat chronic inflammation of the renal pelvis. However, one usually waits for the result of the so-called antibiogram first. This is a microbiological examination that tests the effectiveness of various antibiotics against the pathogen present. In this way, it is possible to find out which antibiotic is best suited for treatment in each individual case. The antibiotic therapy then usually lasts one week, possibly longer. Subsequent episodes of illness are also treated with antibiotics.

If no improvement occurs despite antibiotic treatment, patients with chronic inflammation of the renal pelvis are referred to hospital. There they are administered the drugs as an infusion. Then the therapy often works faster and better.

Removing triggers

In addition, triggers for inflammation of the renal pelvis should be eliminated if possible. If, for example, a constriction in the urinary tract or an enlarged prostate obstructs the flow of urine and thus promotes pyelonephritis, surgery is often necessary.

Inflammation of renal pelvis: causes and risk factors

There are various reasons for inflammation of the renal pelvis. In most cases, the cause is an ascending bacterial infection: the pathogens reach the renal pelvis via the urethra, bladder and ureter. Therefore, inflammation of the renal pelvis is often preceded by urethritis or cystitis. Only rarely do the bacteria that cause pelvic inflammatory disease enter the body via the bloodstream.

In almost 80 per cent of all cases, the intestinal bacterium Escherichia coli (E. coli) is the trigger of pyelitis: If the germ is carried from the anus into the urethra (e.g. due to lack of intimate hygiene), it can rise up to the kidneys. Sometimes other bacteria (such as enterococci, staphylococci) as well as fungi or viruses also cause pelvic inflammatory disease.

Women are about two to three times more likely to suffer from pyelonephritis than men. This is partly because they have a shorter urethra and their entrance is closer to the anus. (intestinal) bacteria can therefore more easily enter the bladder and from there to the kidneys.

Inflammation of renal pelvis: Risk factors

There are numerous risk factors that favour inflammation of the renal pelvis. These include, for example, urinary flow disorders: The renal pelvis serves as a collection funnel for the urine produced in the kidney and drains it via the ureters. If the urine cannot flow or can flow at a reduced rate, it accumulates. This promotes bacterial growth and thus inflammation of the renal pelvis. Urinary flow disorders can be congenital, for example if the ureter has a congenital constriction. However, they can also be acquired, for example in cases of prostate enlargement, urinary or bladder stones and infections.

In summary, the following risk factors apply to inflammation of the renal pelvis:

  • advanced age
  • Pregnancy (under the influence of hormones, the urinary tract widens, which makes it easier for bacteria to ascend)
  • Kidney stones or bladder stones
  • Bladder catheter over a longer period of time (permanent catheter)
  • reduced hormone production (e.g. after the menopause)
  • Lower urinary tract infections
  • Metabolic diseases, e.g. diabetes mellitus
  • enlarged prostate (prostate hyperplasia) in men
  • congenital deformities of the kidney
  • vesicoureteral reflux: urinary reflux from the bladder towards the kidney (e.g. due to a leaky opening of the ureter into the bladder)
  • general immunodeficiency (e.g. in case of HIV infection)

Inflammation of renal pelvis: examinations and diagnosis

A doctor will first take your medical history (anamnesis): He will ask you about your complaints and any pre-existing and underlying illnesses. Possible questions here are:

  • What exactly are your complaints? How long have they existed?
  • Have you had an infection of the lower urinary tract (such as cystitis) in the past few months?
  • Do you have kidney stones or bladder stones?
  • Do you suffer from metabolic diseases such as diabetes mellitus?

Physical examination

The doctor then carries out a thorough physical examination. Among other things, he taps and palpates the kidneys, as pain in the flanks is typical for inflammation of the renal pelvis.

Urine examination

The analysis of a urine sample is very important in the diagnosis of a renal pelvic inflammation: one checks whether bacteria and white blood cells (leukocytes) can be found in the urine and if so, in what quantity. An increased number of both parameters indicates an inflammation of the urinary tract.

A urine culture is used to identify the pathogen: The urine sample is exposed to conditions that are ideal for bacterial growth. This allows the pathogen to multiply in the sample and then easily detect it. In addition, an antibiogram will be prepared: The effectiveness of various antibiotics against the pathogen in question is therefore tested. This helps with therapy planning.

Blood test

Particularly if chronic inflammation of the renal pelvis is suspected, a blood sample is taken and analysed in the laboratory. One measures the inflammation parameters such as the blood sedimentation rate (BSG) and the C-reactive protein (CRP). Both values indicate inflammation in the body when they are elevated.

In addition, the creatinine value is determined during the blood analysis. An elevated level can be a warning sign that the kidneys may already be damaged.

Imaging methods

With the help of a conventional ultrasound examination (sonography), the doctor can assess the position, shape and size of the kidneys. Also urinary and kidney stones as well as a possible urinary retention as a trigger of the inflammation can be detected. In addition, ultrasound can be used to identify scar tissue in the kidneys as it is formed in chronic inflammation of the renal pelvis.

A special form of ultrasound examination is the micturition sonography. It is often used for children. This involves an ultrasound examination to determine whether the urine is flowing from the bladder back towards the kidneys (vesicoureteral reflux), which promotes inflammation of the renal pelvis. Prior to the examination, the patient is given a contrast medium which makes urine reflux more visible.

In some cases of inflammation of the renal pelvis, other imaging procedures are also useful. For example, computer tomography (CT) can be used if the findings of the ultrasound examination are unclear. An X-ray examination of the urinary tract (urography) can detect, among other things, narrowing of the urinary tract as well as urinary or kidney stones.

Inflammation of renal pelvis: course and prognosis

If an acute inflammation of the renal pelvis is detected and treated in time, the prognosis is generally good. It then heals without consequences. The doctor usually checks the success of treatment by means of a urine examination two weeks after the end of therapy. If no more pathogens are then detectable, the inflammation is considered to have healed.

A chronic inflammation of the renal pelvis is threatened if acute pyelonephritis is treated too late or insufficiently. The prognosis is then less favourable. In many cases, chronic pyelonephritis does not completely heal. The recurrent inflammatory flare-ups must be treated with antibiotics to avoid more serious complications. Regular medical check-ups are also necessary.

Untreated, both forms of inflammation of the renal pelvis cause severe damage to the kidney. Ultimately, this can lead to complete renal failure (renal insufficiency).

A further possible complication of inflammation of the renal pelvis is an encapsulated accumulation of pus in the tissue (renal abscess). This must be treated quickly, otherwise it can become dangerous.

In addition, there is a risk of so-called urosepsis in the case of inflammation of the renal pelvis. This is known as “blood poisoning” (sepsis), which starts in the urinary tract and spreads throughout the body from the kidneys via the bloodstream. This can be life-threatening under certain circumstances!

Inflammation of the renal pelvis: Prevention

There are some measures you can take to reduce the risk of pelvic inflammatory disease:

  • Drink sufficiently and regularly (e.g. water or tea). This cleans the urinary tract and flushes out any germs.
  • Regular urination also helps to flush pathogens from the urinary tract. Especially after sexual intercourse you should go to the toilet soon.
  • Women should always wipe from the vagina to the anus after defecation. In the opposite case, it is easy for intestinal bacteria to be carried from the anus to the nearby urethral opening.
  • Appropriate intimate hygiene is advisable for both sexes to prevent inflammation of the renal pelvis. Both inadequate and excessive intimate hygiene can promote the growth of germs. For example, do not use disinfectants for intimate hygiene, only warm water.
  • A bladder infection can lead to an inflammation of the renal pelvis. Therefore avoid hypothermia by wearing suitably warm clothing. Change wet clothes (e.g. wet swimwear or sweaty sportswear) as soon as possible.
  • In the case of recurrent inflammation of the renal pelvis, a so-called prophylaxis to prevent infection may be considered. Those affected must take a low dose of antibiotics over a longer period of time (initially six months) as a preventive measure.
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Sandra Eades
Hello I am Sandra Eades, physician, researcher and author from Australia. I am working currently as researcher for a private institution. I have studied in Britain and Australia, where I currently reside. I write about research topics in the organization of the public health government agencies. For the iMS I write about general medical conditions. I also research scholar sources to provide information to writers of other articles. I also check the citations of scholar papers. Finally, I read other articles before they are published. I am also a mother of three children!