A urinary tract infection (UTI) occurs when bacteria enter and multiply within the urinary system. Proteinuria refers to the presence of an increased amount of protein in the urine. While the kidneys are designed to filter waste from the blood, they normally retain most proteins. Their appearance in urine can signal an issue. This connection is often observed, raising questions about why UTIs might cause protein in urine.
Understanding UTIs and Proteinuria
Urinary tract infections occur when bacteria, often Escherichia coli (E. coli) from the digestive tract, enter the urethra and move into the bladder. These infections can affect any part of the urinary system, including the urethra, bladder, and kidneys. Common symptoms include a frequent urge to urinate, a burning sensation during urination, cloudy or foul-smelling urine, and lower abdominal discomfort.
The kidneys filter waste products and excess water from the blood to produce urine. Proteins are large molecules that serve various functions in the body. Normally, the tiny filters within the kidneys, called glomeruli, prevent these large protein molecules from passing into the urine, reabsorbing them back into the bloodstream. Finding protein in the urine (proteinuria) indicates this filtering process may not be working efficiently. Proteinuria can be temporary or persistent.
The Link Between UTIs and Proteinuria
The primary reason a UTI can lead to protein in the urine is inflammation. When bacteria infect the urinary tract, the body’s immune system responds, causing inflammation. This inflammation can affect urinary tract tissues, including the bladder and, if the infection spreads, the kidneys.
If the infection reaches the kidneys, a condition known as pyelonephritis, the inflammation can directly impact the glomeruli, the kidney’s filtering units. This inflammatory response can make these tiny filters temporarily more permeable, allowing small amounts of protein, such as albumin, to leak from the bloodstream into the urine. This proteinuria is usually mild to moderate and resolves once the bacterial infection is treated.
More significant levels of proteinuria during a UTI could suggest a more severe infection or one that has spread to the kidneys. The presence of red blood cells and protein in urine during a UTI can indicate more severe kidney involvement, requiring thorough investigation.
What to Do About Proteinuria During a UTI
It is important to seek medical attention for a UTI to ensure prompt diagnosis and appropriate treatment. Early antibiotic treatment is effective in clearing the bacterial infection, which helps resolve associated proteinuria. Completing the full course of prescribed antibiotics is advised, even if symptoms improve, to ensure the infection is fully eradicated and to prevent complications.
If protein is detected in urine during a UTI, healthcare providers will advise following the prescribed treatment plan. After the infection has cleared, follow-up testing for proteinuria may be recommended. This re-evaluation helps confirm protein levels have returned to normal, especially if initial levels were high or kidney involvement was a concern. Persistent proteinuria after a UTI has been treated could indicate an underlying kidney issue or another condition requiring further investigation.