Inflammation of the renal pelvis (pyelonephritis): causes, symptoms and treatment

Pyelonephritis is a serious kidney infection that is usually caused by a urinary tract infection that has spread upward. Bacteria travel from the bladder up through the ureters into the renal pelvis and the surrounding kidney tissue. The severity of this condition is comparable to that of severe pneumonia and requires immediate medical treatment.

Symptoms of pyelonephritis

The signs of pyelonephritis are usually distinct and appear suddenly:

• Severe flank pain: Intense pain in the side of the back at the level of the kidneys
• High fever: Often above 38.5 °C, accompanied by chills
• Back pain: Dull to stabbing pain that may radiate to the lower abdomen
• General feeling of illness: Nausea, fatigue, and weakness

In addition, typical symptoms of a bladder infection, such as a burning sensation when urinating and frequent urge to urinate, may be present.

Why is prompt treatment so important?

If pyelonephritis is not treated promptly and properly, serious complications may arise:

• Acute kidney failure: The kidneys may lose their filtering function
• Blood poisoning (sepsis): Bacteria enter the bloodstream—a life-threatening condition
• Chronic kidney damage: Recurrent infections can permanently impair kidney function
• Kidney loss: In the worst-case scenario, a kidney may need to be removed

When should you see a urologist?

If you are experiencing flank pain accompanied by fever and chills, you should schedule an appointment with a urologist as soon as possible. Early diagnosis through blood and urine tests as well as imaging studies allows for targeted treatment and prevents serious complications.