Can Endometriosis Cause Blood In Urine? | When It Happens

Yes, tissue growing on the bladder or urinary tract can lead to blood in urine, often around a period, but other causes need a prompt check.

Blood in urine can feel jarring. Endometriosis can reach the bladder or ureters, and that can cause bleeding or pain with urination.

Do not pin this symptom on endometriosis alone. A urine infection, kidney stone, blood mixed into the sample during menstruation, kidney disease, or a bladder problem can also cause it. The timing, the rest of your symptoms, and a few tests help sort out what fits best.

Can Endometriosis Cause Blood In Urine? Clues That Fit

Yes, it can. Endometriosis is tissue similar to the lining of the uterus growing outside the uterus. Most cases stay in the pelvis. A smaller share reaches the urinary tract, most often the bladder and less often the ureters.

When those spots react to monthly hormone shifts, they can swell, irritate nearby tissue, and bleed. That may show up as visible blood in urine or blood found only on a test. The clue doctors listen for is timing. If the bleeding shows up during your period, or right before it, urinary tract endometriosis moves higher on the list.

Signs that make this pattern stand out include:

• Blood in urine that follows the same monthly rhythm
• Pain or burning when you pee near your period
• Bladder pressure, urgency, or needing to pee more often
• Pelvic pain, period pain, or pain with sex at the same time
• A known history of endometriosis in the pelvis or bowel

Bladder endometriosis may cause pressure behind the pubic bone or a sharp sting as the bladder fills. Ureter disease can be harder to spot and may cause few early symptoms. That is one reason blood in urine deserves a real workup, even when it comes and goes.

Why The Timing Matters

NICE lists period-related urinary symptoms, mainly blood in the urine or pain when passing urine, among the signs that should raise suspicion for endometriosis. If deep disease reaches the bladder or ureter, referral to a specialist service is part of that workup.

Still, the calendar is not perfect. Some people have daily bladder pain. Some only learn about ureter disease after a swollen kidney appears on imaging. So the cycle pattern helps, but it does not settle the question by itself.

Other Causes That Need A Prompt Check

Blood in urine has a long list of causes. On the NIDDK’s hematuria page, common causes include infection, stones, trauma, kidney disease, and endometriosis, with cancer also on the list. That is why doctors treat urine bleeding as a finding to sort out, not as a symptom to brush aside.

A sample collected during a period can muddy the picture. Menstrual blood may mix with the urine and create a false alarm. If the sample was taken while bleeding, many clinicians repeat the test after the period ends.

Clues that often point away from endometriosis and toward another urinary problem include:

• Fever, chills, or cloudy, bad-smelling urine
• Severe side or back pain that comes in waves
• A first episode with no tie to the menstrual cycle
• Blood clots in urine or trouble emptying the bladder
• Older age, smoking history, or repeat bleeding without pelvic symptoms

Possible Cause	Pattern Often Seen	Clues That May Travel With It
Bladder endometriosis	Bleeding or pain tied to the menstrual cycle	Pelvic pain, urgency, pain when peeing, bladder pressure
Ureter endometriosis	May be silent or cycle-linked	Flank pain, kidney swelling on imaging, fewer bladder symptoms
Urine infection	Can start suddenly	Burning, frequency, fever, cloudy or strong-smelling urine
Kidney stone	Sudden episodes	Sharp side pain, nausea, restlessness, blood in urine
Menstrual sample contamination	Positive test only during a period	No urinary source when retested after bleeding ends
Kidney disease	May be found on routine testing	Protein in urine, swelling, high blood pressure, dark urine
Bladder or kidney tumor	Can be painless and repeat	Visible blood, clots, age or smoking risk, no cycle pattern
Medicine or trauma	After a new drug, hard exercise, or injury	Recent blood thinners, strain, falls, or procedures

How Doctors Sort Out The Cause

The first step is usually a history and a urine test. Your clinician will want to know when the blood shows up, whether you also have pain with urination, whether it tracks your period, and if you already have an endometriosis diagnosis. ACOG’s endometriosis FAQ notes that endometriosis can affect the bladder, bowel, and other organs, so urinary symptoms do not rule it out.

A urinalysis can confirm that blood is truly present. A lab check for infection may be added. If the sample was collected during menstruation, repeating it later may clean up the picture. Blood tests may be added if there is concern about kidney strain or ongoing blood loss.

Imaging depends on the pattern. Pelvic ultrasound can rule out some pelvic causes. Kidney and bladder ultrasound can show swelling, stones, or a mass. MRI may be used when deep endometriosis is suspected, mainly if the bladder or ureter may be involved. Cystoscopy, a camera test inside the bladder, is used in selected cases when a bladder lesion or another source of bleeding needs a direct view.

NICE endometriosis guidance also flags cyclical urinary symptoms as a reason to suspect endometriosis. If the bladder or ureter may be involved, care often shifts to a team with both gynecology and urology input. That matters most with ureter disease, since a blocked ureter can slowly injure a kidney without much warning.

Treatment Depends On Where The Bleeding Starts

If the source is infection, stones, kidney disease, or another bladder issue, treatment goes after that cause. If urinary tract endometriosis is the source, treatment depends on the site, depth, symptom burden, and whether the kidney or ureter is under stress.

Hormonal treatment may ease cycle-linked bleeding and pain. Surgery may be advised when a lesion grows into the bladder wall, when pain stays stubborn, or when the ureter is narrowed. With ureter disease, the goal is also to protect kidney drainage before lasting damage sets in.

A person with mild bladder symptoms may start with medicine and monitoring. A person with a blocked ureter may need a stent, a nephrostomy, or surgery much sooner. The right plan comes from the exact site and the test results, not from the word endometriosis by itself.

Situation	Usual Next Step	Why It Should Not Wait Too Long
Blood in urine only during a period, no red flags	Book a clinic visit and urine test	Cycle timing may point to endometriosis, but the source still needs proof
Blood in urine with burning or fever	Same-day check	Infection can move upward and worsen fast
Blood in urine with side or back pain	Urgent review	Stone or ureter blockage may be present
Visible clots or trouble peeing	Urgent care	Clots can block urine flow
Known endometriosis plus new urinary bleeding	Gynecology or urology review	A urinary tract site may need imaging
Repeat episodes with no cycle pattern	Full hematuria workup	Other urinary causes still need to be ruled out

When To Get Help Right Away

Do not sit on these symptoms:

• Blood clots in urine
• Fever, vomiting, or feeling faint
• Sharp side pain, mainly on one side
• Trouble peeing or no urine coming out
• Heavy bleeding while pregnant
• A known single kidney or prior kidney disease

If you suspect the bleeding follows your cycle, say that clearly when you book the visit. That one detail can change the type of imaging ordered and the specialist you see. It can also stop the symptom from being written off as a random urine infection.

Questions To Bring To Your Visit

• Was the blood visible, or only found on a test?
• Should my urine test be repeated after my period ends?
• Do my symptoms fit bladder endometriosis, ureter disease, a stone, or infection?
• Do I need urinary imaging, pelvic imaging, or both?
• Should I see gynecology, urology, or both?

If blood in urine keeps showing up near your period, that pattern deserves a proper workup. Endometriosis can be the reason, mainly when the bladder or ureter is involved. Still, it is only one item on the list. Treat the bleeding as real, get it checked, and push for answers that match both your cycle and your urine findings.