A urinary tract infection (UTI) is a common condition caused by a bacterial invasion, typically Escherichia coli, affecting parts of the urinary system, such as the urethra or bladder. This infection causes inflammation in the lining of these structures, leading to a range of uncomfortable symptoms. One alarming symptom is the presence of blood in the urine, medically termed hematuria. This symptom is often directly linked to the inflammatory response of the infection.
Why a UTI Can Cause Blood
Blood appears in the urine because the bacterial infection irritates the delicate mucosal lining of the urethra and the bladder wall. When bacteria colonize the urinary tract, they trigger an inflammatory response. This inflammation causes tissues to swell and become fragile, leading to minor damage to small, superficial blood vessels. Red blood cells then leak out of the damaged capillaries and mix with the urine.
The resulting blood manifests in two forms. Microscopic hematuria is not visible to the naked eye; a healthcare provider must view the urine under a microscope to confirm red blood cells. Gross hematuria is visible and can turn the urine pink, bright red, or a brownish, cola-like color.
While visible blood can be frightening, it usually indicates localized inflammation of the lower urinary tract (cystitis). Any amount of visible blood in the urine warrants immediate medical evaluation to determine its source.
Other Common Signs of a UTI
A lower urinary tract infection presents with a distinct set of irritating symptoms. One common complaint is dysuria, a sensation of pain or burning during urination. This discomfort is caused by the inflamed urethra and bladder neck. Patients also experience urinary frequency, needing to urinate much more often than usual.
Frequency is often accompanied by urgency, a sudden, strong need to empty the bladder, even if it was recently emptied. Despite the constant urge, only small amounts of urine are passed. The infection can also cause physical pressure or discomfort in the lower abdomen, specifically above the pubic bone. This suprapubic tenderness results from bacteria-induced inflammation within the bladder. Urine may also appear cloudy or have a strong, unpleasant odor.
Recognizing Severe Symptoms and Complications
If UTIs ascend the ureters and reach the kidneys, this serious complication is known as pyelonephritis. This upper tract infection requires immediate medical attention. Pyelonephritis is marked by severe, systemic symptoms that extend beyond the lower urinary tract.
Signs that the infection has spread to the kidneys include fever, often accompanied by chills. Patients may also experience nausea and vomiting, indicating a systemic illness. A distinguishing symptom is flank pain, a deep, aching discomfort felt in the back or side, usually just below the ribs, corresponding to the location of the kidneys.
Hematuria, whether microscopic or gross, can also signal causes other than a UTI. Conditions such as kidney stones, which physically scrape the urinary tract lining, or underlying issues like kidney disease or bladder cancer, can cause blood in the urine. Persistent or recurring blood in the urine, especially without other infection symptoms, requires a thorough investigation to rule out these complex diagnoses.
Seeking Diagnosis and Treatment
When UTI symptoms, particularly bleeding, appear, consult a healthcare provider for diagnosis. The process begins with a medical history review and a urine test. The provider collects a clean-catch urine sample, which is analyzed in two ways.
A urinalysis uses a dipstick and microscopic examination to look for signs of infection, such as red blood cells, white blood cells (pyuria), and bacteria. A urine culture is then performed, sending the sample to a lab to identify the specific type of bacteria causing the infection. Identifying the bacteria helps the physician select the most effective antibiotic.
Treatment for a confirmed bacterial UTI involves a short course of oral antibiotics, selected based on culture results and local resistance patterns. Complete the entire course of medication as prescribed, even if symptoms improve quickly, to ensure the infection is fully eradicated and prevent antibiotic resistance. Supportive care, such as increasing fluid intake and using over-the-counter pain relievers, can help manage discomfort until the antibiotics take effect.