Can a UTI Spread to the Kidneys?

Yes. A UTI that starts in the bladder can sometimes spread upward through the urinary tract and reach the kidneys, causing a kidney infection (pyelonephritis). Kidney involvement is more serious than a lower UTI and requires prompt medical evaluation and treatment.

Most UTIs affect the lower urinary tract, particularly the bladder. However, bacteria can sometimes travel upward through the ureters and infect the kidneys.

Signs that a UTI may have spread to the kidneys can include:

• Fever and chills
• Pain in the back or side, particularly around the kidney area
• Nausea or vomiting
• Burning or pain while urinating
• Frequent or urgent urination
• Blood or changes in the urine
• Feeling unusually weak or unwell

The risk of complications can be higher when there is urinary obstruction, kidney or urinary stones, significant residual urine, or another abnormality affecting urine flow.

A kidney infection should not be managed as though it were simply a mild bladder infection. Depending on the symptoms and severity, evaluation may involve urine testing, urine culture, blood tests, and sometimes imaging to look for obstruction, stones, or other complications.

If someone with UTI symptoms develops high fever, chills, severe back or side pain, vomiting, confusion, or significant deterioration, prompt medical attention is important because a severe urinary infection can potentially progress to systemic infection.

SCI International Hospital

At SCI International Hospital, Dr. Gautam Banga evaluates patients with recurrent or severe urinary infections to determine whether the infection may have involved the kidneys or whether an underlying condition is contributing to the problem. When appropriate, evaluation may include urine and blood tests and imaging to check for stones, obstruction, urinary retention, or other urological abnormalities.