Blood in the urine, medically termed hematuria, is a symptom that causes concern. Hematuria is classified as either gross, meaning the blood is visible and changes the urine color to pink, red, or brown, or microscopic, where blood cells are only detectable under a microscope during a lab test. Many individuals taking hormonal contraceptives worry about a connection between their medication and this alarming symptom. While a direct cause is rare, common, unrelated urinary conditions or certain indirect risks can lead to blood in the urine.
Direct Impact of Hormonal Birth Control on the Urinary Tract
Hormonal birth control methods, such as pills, patches, and rings, primarily regulate estrogen and progestin to prevent ovulation. These hormones act on the reproductive system, specifically the lining of the uterus. The urinary tract, which includes the kidneys, ureters, bladder, and urethra, is structurally separate from the reproductive organs.
The steroid hormones in contraceptives do not have a direct toxic effect on the urinary tract lining (urothelium) that would cause bleeding. Breakthrough bleeding, a common side effect, is often confused with hematuria but originates from the shedding of the uterine lining due to hormonal adjustment. This unscheduled bleeding from the vagina is distinct from blood originating from the bladder or kidneys and is most common during the first three to six months of starting a new method.
Common Non-Hormonal Causes of Blood in Urine
Since a direct link between birth control hormones and hematuria is largely absent, the presence of blood in the urine is usually due to common, unrelated conditions.
Urinary Tract Infections (UTIs)
One of the most frequent causes is a Urinary Tract Infection (UTI), which occurs when bacteria, most often Escherichia coli, multiply within the urinary system. The infection causes inflammation and irritation of the bladder or urethral lining, damaging small blood vessels and causing red blood cells to leak into the urine. This irritation is often accompanied by symptoms like painful or frequent urination and a constant urge to void.
Kidney or Bladder Stones
Another common source of hematuria is the movement of kidney or bladder stones, which are hardened mineral deposits. These stones often have rough edges that physically scrape and injure the lining of the ureters or kidneys as they pass. This mechanical trauma ruptures small blood vessels, resulting in bleeding. A stone can also cause a partial blockage, leading to increased pressure that contributes to tissue damage and bleeding.
Physical Activity and Contamination
Vigorous physical activity, particularly high-impact exercise like long-distance running, can cause transient hematuria, sometimes called “runner’s bladder.” This results from the repeated impact of the bladder walls rubbing against each other. Exercise-induced bleeding is usually painless and resolves spontaneously within 24 to 72 hours of rest. Additionally, if a urine sample is collected during menstruation, blood from the vagina can contaminate the specimen, leading to a false-positive result for hematuria.
When Blood Clotting Risk Leads to Kidney Issues
A rare but serious indirect link between hormonal birth control and hematuria involves the increased risk of blood clots. Combined hormonal contraceptives, which contain estrogen, elevate the risk of Venous Thromboembolism (VTE) by increasing clotting factors. This clotting propensity can, in rare instances, affect the renal system.
The resulting serious complication is Renal Vein Thrombosis (RVT), the formation of a blood clot in the vein that drains the kidney. When the renal vein is blocked, the kidney experiences severe congestion and swelling because blood cannot exit properly. This congestion injures the delicate filtering units, leading to the leakage of blood into the urine.
RVT is a medical emergency that typically presents with the sudden onset of severe, acute flank pain, nausea, and vomiting. Although RVT is an uncommon complication of birth control use, hematuria coupled with acute, severe pain requires immediate medical evaluation to prevent potential kidney damage.
Immediate Steps and Medical Consultation
Observing blood in the urine, especially if it is visible (gross hematuria), should always prompt a visit to a healthcare provider. Immediate emergency care is necessary if the hematuria is accompanied by severe symptoms like an inability to urinate, the passage of large blood clots, or blood along with a high fever, chills, or sudden, severe flank or abdominal pain. These symptoms may indicate an obstruction, a severe infection, or a blood clot.
A medical evaluation typically begins with a thorough history and a physical exam, followed by laboratory tests. A microscopic urinalysis is performed to confirm the presence of red blood cells, as a dipstick test alone can sometimes yield a false-positive result. If an infection is suspected, a urine culture is ordered to identify the specific bacteria and determine the appropriate antibiotic treatment.
Depending on the findings, imaging tests may be necessary to view the upper urinary tract for stones or other issues; CT urography is often the preferred method. For visible hematuria, a cystoscopy may be performed, which involves inserting a small camera into the bladder to directly visualize the lower urinary tract lining. Patients should inform the doctor about all medications, including any form of birth control, to ensure an accurate diagnostic workup.