Pyelonephritis

Definition: Pyelonephritis 

A pyelonephritis, also known under the lay term kidney infection, usually occurs as a complication of a pre-existing urinary tract infection (UTI) that ascends to the kidney. 

Therefore, in most cases of pyelonephritis pathogens directly ascend from the infected bladder through the ureters to the kidneys, where they cause an inflammatory response.  Women are significantly more often affected. 

The classic symptoms of pyelonephritis are fever and flank pain. However, the clinical presentation can vary significantly between patients. Additional symptoms may be painful urination (dysuria), chills, nausea and vomiting. In rare cases, pyelonephritis can present without any symptoms. 

The treatment always involves antibiotic therapy, and the condition has a very good prognosis when caught and treated early.

How does pyelonephritis develop?

In most cases, pyelonephritis develops when a UTI ascends through the ureters to the kidneys. This can occur following a prolonged UTI. 

Some patient groups are more prone to developing pyelonephritis than others. This includes patients with a urinary catheter, patients with anatomical urinary tract abnormalities, and people who suffer from frequently occurring UTIs.

Generally, women are more frequently affected than men. This is partially due to the anatomically shorter urethra in women, which facilitates the development of UTIs and pyelonephritis. 

Symptoms and clinical features

The classical symptoms of pyelonephritis are fever, flank pain, and in some cases nausea and vomiting. Fever develops as a reaction to the ongoing inflammation triggered by the body’s immune system. Patients often complain of chills. 

The flank pain is usually located on the affected side. However, in some cases flank pain can be felt on both sides. In addition, patients may experience painful urination. This particularly applies to female patients.

Overall, the clinical condition can vary significantly between patients. While some patients may feel extremely ill, weak and experience pronounced symptoms, others have few or no apparent symptoms. Therefore, a thorough medical assessment is crucial to establish a reliable diagnosis of pyelonephritis.

Is pyelonephritis possible without a fever?

Pyelonephritis can also present without a fever. As mentioned in the paragraph above, the clinical presentation can vary significantly between patients. Thus, pyelonephritis without the presentation of classic symptoms is referred to as atypical pyelonephritis. Fever may also be absent or intermittent in chronic pyelonephritis. Therefore, pyelonephritis should never be ruled out purely based on the absence of fever.

Is pyelonephritis contagious?

Pyelonephritis is not contagious. It is usually caused by bacteria that originate from the gastrointestinal tract and enter the urethra and bladder by ascending through the urinary tract. Therefore, regular hygiene measures are recommended for the prevention of recurrent infections.

How is pyelonephritis diagnosed?

The diagnosis of pyelonephritis is based on a combination of physical examination, urinalysis, and an ultrasound examination of the kidneys. 

During the physical examination, the physician taps over the flank region, which usually causes pain on the affected side.

Various parameters are assessed during urinalysis. The examination allows the assessment of the presence of inflammation and can also aid in identifying the causative pathogen. This is helpful for determining the type of antibiotic, as not every pathogen responds to every antibiotic.

The ultrasound examination of the kidney allows the treating physician to visualize possible structural changes of the kidneys that may occur as a result of the infection.

Treatment and management

The treatment of pyelonephritis always involves antibiotic therapy. The exact choice of antibiotic depends on several factors. For example, the severity of the infection plays an important role when choosing the right antibiotic. Another important factor is identifying the causative pathogen of the pyelonephritis. As not every bacterium responds to every kind of antibiotic, this can make the selection of an appropriate treatment without prior identification of the causative pathogen difficult.

In addition to antibiotic therapy, adequate fluid intake is crucial. It helps the kidneys maintain their important function while they are strained by the infection. If the presenting symptoms include difficulty urinating, a urinary catheter may be placed.

Depending on the presence of additional symptoms such as nausea, vomiting or fever, further medications may be prescribed to relieve them.

Which physicians are specialized in the treatment of pyelonephritis?

The initial diagnosis or suspicion of pyelonephritis is often made by a general practitioner (GP). In uncomplicated cases, the treatment can also be provided by the GP.

If the pyelonephritis is persistent or recurring, a consultation with a urologist may become necessary. They can perform further investigations to determine the presence of anatomical or structural abnormalities of the urinary tract that may predispose patients to pyelonephritis.

In severe cases hospital admission may become necessary. This allows intravenous administration of antibiotics and close monitoring of the patient. The treatment is usually provided by the urology or nephrology department depending on the specialty available at the hospital and individual clinical course.

Anyone seeking medical treatment naturally wants the best possible medical care. Patients therefore ask themselves: Where can I find the best clinic for me? This question cannot be answered objectively as no reputable physician would claim to be the ‘best’. Therefore, one should only rely on the physician’s experience and expertise.

We want to help you find an expert for your condition. All physicians and clinics listed here have been carefully assessed for their outstanding specialization in the field of pyelonephritis and are available to receive your inquiry or treatment request.