Blood Clots in Bladder Male: 9 Serious Causes

Blood clots in bladder male usually mean that bleeding has occurred somewhere in the urinary system and enough blood has collected to clot. Causes include prostate enlargement, infection, stones, urinary procedures, medicines, trauma, radiation injury, and urinary tract cancer. If clots block urine flow and you cannot urinate, seek urgent medical care.

The clot itself is not the diagnosis.

The real question is: where is the bleeding coming from?

What are blood clots in the bladder?

A urinary blood clot forms when enough blood enters the urinary tract to coagulate.

This is different from a clot that forms inside a leg vein or travels to the lungs.

A bladder clot usually develops because somewhere in the urinary system is bleeding.

The source can be:

• The bladder
• The prostate
• The urethra
• The ureters
• The kidneys

Urine may look pink, bright red, dark red, brown, or cola colored.

You may also see soft clumps, strings, or irregular pieces of clot.

The appearance alone cannot tell you the exact cause.

What is gross hematuria?

Gross hematuria means blood is visible in the urine.

This is different from microscopic hematuria, where the urine looks normal but a laboratory test detects red blood cells.

NIDDK notes that visible hematuria can occur without pain.

Clots change the picture because they may hurt as they pass and can sometimes block urine flow.

For broader kidney and urinary warning signs, see the NextFitLife Kidney Disease Symptoms Guide.

Are bladder blood clots dangerous?

They can be.

A small clot that passes does not automatically mean a medical emergency.

The bleeding still needs evaluation.

The immediate danger occurs when clots collect inside the bladder and block the outlet.

This is called clot retention.

The bladder continues filling with urine but cannot empty properly.

That can cause severe pressure and pain.

1. An enlarged prostate can cause bleeding

Benign prostatic hyperplasia, or BPH, becomes more common as men get older.

The enlarged prostate can squeeze the urethra and make bladder emptying harder.

Typical symptoms include:

• Weak urine stream
• Difficulty starting
• Stopping and starting
• Feeling that the bladder did not empty
• Frequent urination
• Getting up at night to urinate

NIDDK also lists blood in the urine among possible complications of BPH.

If bleeding is heavy enough, clots can form.

Do not assume BPH is the cause simply because you are an older man.

Visible blood still needs evaluation because infection, stones, and cancer can cause similar symptoms.

2. Urinary infection or prostatitis can cause blood

A urinary tract infection can inflame the bladder or other urinary tissues and cause visible blood.

Possible clues include:

• Burning when urinating
• Urgency
• Frequent urination
• Lower abdominal discomfort
• Cloudy urine
• Strong urine odor

In men, urinary infection also raises questions about the prostate and urinary blockage.

Fever, chills, pelvic pain, painful ejaculation, or difficulty passing urine can occur with prostatitis.

Read the NextFitLife UTI Symptoms Guide for the difference between bladder infection, kidney infection, and other urinary problems.

Blood in the urine should not automatically be blamed on infection without follow up.

If visible blood remains after the infection is treated, further evaluation is needed.

3. Kidney or bladder stones can trigger urinary bleeding

Stones can scrape or irritate urinary tissue and cause visible blood in urine.

A kidney or ureter stone often causes:

• Severe side or back pain
• Pain moving toward the groin
• Nausea
• Vomiting
• Urinary urgency
• Blood in urine

Bladder stones can cause lower urinary symptoms, pain, poor stream, and bleeding.

Stones are one reason blood may appear without the source actually being inside the bladder wall itself.

4. Bladder cancer is an important cause to rule out

This section deserves calm wording.

Most people with blood in the urine do not automatically have cancer.

But bladder cancer is one of the reasons visible hematuria should never be ignored.

Bladder cancer risk rises with age and occurs more often in men than women.

Tobacco use is a major preventable risk factor.

NCI explains that chemicals from tobacco enter the blood, are filtered by the kidneys, and collect in urine, exposing the bladder lining.

Other risk factors can include some occupational chemical exposures, previous pelvic radiation, certain chemotherapy medicines, and long term urinary catheter use.

Visible blood can sometimes be the first clue.

It may even be painless.

Does painless blood in urine still need checking?

Yes.

Pain does not determine whether hematuria is serious.

Some cancers cause painless bleeding.

NICE guidance in the United Kingdom recommends urgent suspected cancer referral for adults age 45 and older with visible hematuria that is unexplained by infection or continues after a urinary infection is treated.

Other countries use different referral systems, but the principle is similar.

Visible unexplained blood needs proper evaluation.

5. Bleeding can start higher in the urinary tract

Clots seen in the bladder do not prove that the bladder itself started the bleeding.

The kidneys and ureters sit upstream.

Blood from higher in the urinary tract can flow down into the bladder.

Possible causes include:

• Kidney stones
• Kidney tumors
• Upper urinary tract tumors
• Kidney injury
• Some kidney diseases

This is one reason imaging often forms part of the evaluation.

The urologist is not only looking inside the bladder.

The upper urinary tract may need checking too.

6. Urinary procedures can cause temporary bleeding

Blood can appear after a procedure involving the prostate, bladder, urethra, or urinary catheter.

Examples include:

• Prostate biopsy
• Transurethral prostate surgery
• Bladder surgery
• Cystoscopy
• Catheter placement
• Stone procedures

A small amount of bleeding can be expected after some procedures.

Your surgeon or urology team should tell you what is normal.

Large clots, heavy bright red bleeding, inability to urinate, fever, severe pain, or worsening symptoms are different.

Contact the clinical team or seek urgent care according to your discharge instructions.

7. Trauma can cause urinary bleeding

A strong blow to the abdomen, flank, pelvis, or genital area can injure the kidney, bladder, urethra, or other urinary structures.

Visible blood after significant trauma should be medically assessed.

Do not assume the blood comes from a simple bruise.

Trauma plus inability to urinate, severe abdominal or side pain, dizziness, or fainting requires urgent care.

8. Blood thinners can worsen bleeding but should not end the investigation

Blood thinners and antiplatelet medicines can increase bleeding.

Examples include medicines used to reduce the risk of stroke, heart attack, or dangerous vascular clots.

This creates two common mistakes.

Mistake 1: Blaming the medicine for everything

A blood thinner can make urinary bleeding more noticeable.

It can also reveal bleeding from another problem.

Current hematuria guidance does not recommend ignoring urinary bleeding simply because a person takes anticoagulant or antiplatelet medicine.

Mistake 2: Stopping the medicine yourself

Do not stop a prescribed anticoagulant, aspirin, or antiplatelet medicine because you see urinary blood unless the clinician responsible for your care tells you to do so.

Stopping these medicines can raise the risk of stroke, heart attack, or another serious clotting event in some patients.

Seek medical advice promptly instead.

9. Radiation or some cancer treatments can injure the bladder lining

Previous pelvic radiation can sometimes damage bladder tissue months or years later.

This is called radiation cystitis.

When bleeding becomes significant, the term hemorrhagic cystitis may be used.

Some chemotherapy medicines can also damage the bladder lining.

Symptoms can include:

• Visible blood
• Blood clots
• Urinary frequency
• Urgency
• Bladder discomfort

A previous history of radiation does not mean doctors should automatically blame radiation for new bleeding.

Other causes, including malignancy, infection, and stones, may still need to be excluded.

How do doctors find where the bleeding comes from?

The workup depends on age, symptoms, bleeding severity, medical history, medicines, and cancer risk.

Common parts include:

Urine testing

A urinalysis can confirm blood and look for clues such as infection or protein.

A urine culture may be used when infection is suspected.

Blood tests

Tests can include:

• Complete blood count
• Kidney function
• Electrolytes
• Clotting studies when relevant

The blood count helps show whether significant bleeding has caused anemia.

Imaging

Imaging may examine the kidneys, ureters, and bladder.

Depending on the situation, this can include ultrasound, CT, MRI, or CT urography.

For gross hematuria, CT urography or MR urography can be appropriate ways to evaluate the urinary tract in selected patients.

Cystoscopy

Cystoscopy lets a urologist look directly inside the urethra and bladder using a thin instrument with a camera.

Imaging and cystoscopy answer different questions.

A normal scan does not always replace direct inspection of the bladder when cystoscopy is indicated.

What happens if clots block the bladder?

This is treated in a medical setting.

The goals are to reopen urine flow, clear obstructing clots, and control the bleeding source.

Hospital treatment may include:

• A urinary catheter designed to drain blood and clots
• Bladder irrigation with sterile fluid
• Continuous bladder irrigation when bleeding continues
• Cystoscopy to remove clots
• Treatment of an active bleeding point
• Blood tests and fluid treatment
• Blood transfusion if severe blood loss has occurred

If manual irrigation cannot clear the clots, cystoscopic clot evacuation may be required.

This is not a home procedure.

Do not attempt to insert a catheter or irrigate your bladder yourself unless you have been specifically trained and instructed by your medical team.

Can drinking more water dissolve a bladder blood clot?

No.

Water does not dissolve an established clot that is blocking the bladder outlet.

Good hydration may help maintain urine flow in some situations when a clinician says it is appropriate.

That is very different from treating clot retention.

If you cannot urinate, drinking large volumes can increase bladder pressure and discomfort.

Seek urgent care.

Can cranberry juice clear blood clots?

No.

Cranberry does not dissolve urinary blood clots.

It also does not treat a tumor, stone, enlarged prostate, urinary obstruction, or active bleeding source.

Do not delay evaluation while trying juices, herbs, supplements, or cleansing drinks.

What should you never do when you see urinary blood clots?

• Do not ignore them because the bleeding stopped.
• Do not assume they came from hemorrhoids.
• Do not assume a blood thinner is the only cause.
• Do not stop prescribed anticoagulants on your own.
• Do not force huge amounts of water if you cannot urinate.
• Do not insert urinary equipment yourself unless trained.
• Do not wait for pain before seeking assessment.

Can blood clots in the bladder be prevented?

There is no one method that prevents all urinary blood clots.

The best prevention depends on the cause of the bleeding.

1. Treat prostate obstruction

If BPH is causing poor emptying, bleeding, repeated infection, bladder stones, or retention, follow the treatment plan from your urologist.

Treatment may include medicine or a procedure depending on symptoms and complications.

2. Treat urinary infections properly

Men with suspected UTI symptoms should seek medical assessment rather than repeatedly self treating.

See the NextFitLife UTI Treatment Guide for safer symptom and testing guidance.

3. Prevent recurrent stones when possible

Stone prevention depends on stone type, urine tests, diet, medicines, fluid needs, and medical history.

Do not use one universal “kidney stone cleanse.”

4. Stop smoking

This is one of the clearest modifiable steps.

Tobacco is a major bladder cancer risk factor.

Stopping smoking lowers future risk and benefits the heart, lungs, blood vessels, and kidneys too.

5. Follow instructions after urinary procedures

If a urologist gives you instructions about activity, fluid intake, catheter care, medicines, and warning signs, follow them closely.

Contact the team if the bleeding becomes heavier or clots appear.

6. Manage blood thinners with the prescriber

Make sure every clinician knows which anticoagulant, aspirin, or antiplatelet medicine you use.

Do not change the dose yourself.

7. Keep urology follow up after radiation injury or cancer treatment

Previous pelvic radiation or bladder affecting chemotherapy changes the differential diagnosis for later bleeding.

New visible blood still deserves evaluation.

Does diet prevent blood clots in the bladder?

No specific diet prevents every episode of urinary bleeding.

Diet can help with some underlying problems.

For example, a stone prevention plan may reduce future stones in the right patient.

Good hydration can be useful for some urinary conditions.

But neither water nor food can reliably prevent bleeding caused by bladder cancer, prostate procedures, radiation injury, severe BPH, or a bleeding disorder.

For general healthy lifestyle guidance, see the NextFitLife General Wellness and Healthy Lifestyle Guide.

When should a man with blood in urine see a urologist?

Visible blood should be medically assessed even if it appears only once.

Referral urgency depends on age, infection status, cancer risk, severity, and local healthcare guidelines.

Assessment becomes especially important if you:

• Pass clots
• Are middle aged or older
• Smoke or previously smoked
• Have repeated episodes
• Have unexplained weight loss
• Have urinary obstruction symptoms
• Have persistent blood after UTI treatment
• Have a history of urinary cancer
• Had pelvic radiation
• Have significant occupational chemical exposure

When is blood in urine an emergency?

If urine flow stops because of clots, do not wait for the problem to clear on its own.

Seven myths about bladder blood clots in men

Myth 1: A bladder blood clot is the same as a DVT

No.

A urinary clot is usually coagulated blood from bleeding somewhere in the urinary tract.

Myth 2: No pain means the bleeding is harmless

No.

Visible hematuria can be painless even when the cause needs treatment.

Myth 3: If the blood stops, no testing is needed

No.

Visible unexplained hematuria should still be evaluated.

Myth 4: Blood thinners explain everything

No.

They can worsen bleeding, but an underlying urinary cause may still be present.

Myth 5: Drinking lots of water will dissolve the clot

No.

Obstructing clot retention needs medical treatment.

Myth 6: All blood in an older man comes from the prostate

No.

The bladder, kidneys, ureters, urethra, stones, infection, and cancer all need consideration.

Myth 7: Blood in urine always means cancer

No.

Many noncancer causes exist.

Cancer still matters enough that unexplained visible blood should not be ignored.

Conclusion

Blood clots in bladder male are a sign that enough urinary bleeding has occurred for blood to coagulate. The cause may be BPH, infection, stones, a procedure, trauma, medicine, radiation injury, kidney disease, or urinary cancer.

Your next step should not be a home remedy. If you see visible blood or clots, arrange medical assessment. If clots are blocking urine flow, the lower abdomen is becoming painful and swollen, or bleeding is heavy, seek urgent care now.

Internal Links and NextFitLife Health Guides

• 
  UTI Symptoms Guide
  
  for burning, urgency, frequency, blood in urine, male UTI symptoms, kidney infection warning signs, and testing.
• 
  UTI Treatment and Relief Guide
  
  for safer symptom relief, urine testing, antibiotics, male UTI assessment, and urgent warning signs.
• 
  Kidney Disease Symptoms Guide
  
  for blood in urine, foamy urine, swelling, kidney testing, kidney function, and red flags.
• 
  General Wellness and Healthy Lifestyle Guide
  
  for smoking cessation, preventive care, physical activity, healthy eating, sleep, and long term health habits.

References and Sources

1. National Institute of Diabetes and Digestive and Kidney Diseases. Hematuria: Blood in the Urine.
   
   https://www.niddk.nih.gov/health-information/urologic-diseases/hematuria-blood-urine
   
2. American Urological Association. Urologic Emergencies.
   
   https://www.auanet.org/Documents/education/Urologic-%20Emergencies-AUA-Med-Student.pdf
   
3. American Urological Association and Society of Urodynamics, Female Pelvic Medicine and Urogenital Reconstruction. Microhematuria Guideline, Amended 2025.
   
   https://www.auanet.org/documents/Guidelines/PDF/2025%20Guidelines/MH%20Unabridged%2002.2025FINAL3-1.pdf
   
4. NICE. Kidney Cancer Quality Standard: Visible Haematuria Referral, 2026.
   
   https://www.nice.org.uk/guidance/qs215/chapter/Quality-statement-1-Suspected-cancer-pathway-referral
   
5. National Cancer Institute. Bladder Cancer Causes and Risk Factors.
   
   https://www.cancer.gov/types/bladder/causes-risk-factors
   

About the Author

Adel Galal is the Founder and Lead Writer at NextFitLife. He researches practical health, fitness, nutrition, urinary health, kidney health, men's health, symptom awareness, and healthy aging topics using recognized medical, government, hospital, and professional sources.

His approach to urinary symptom articles is to separate the symptom from the diagnosis. A blood clot in the bladder tells you bleeding occurred, but it does not tell you whether the cause was a prostate problem, infection, stone, procedure, medicine, radiation injury, kidney source, or cancer.

For this article, Adel reviewed current NIDDK, AUA, NICE, and National Cancer Institute information on visible hematuria, clot retention, urinary evaluation, bladder cancer risk, and emergency treatment.

Adel is not a doctor, urologist, nephrologist, oncologist, pharmacist, nurse, or other licensed healthcare professional.

Learn more about Adel Galal, NextFitLife, and the site's editorial standards on the About Us page.

Medical Disclaimer: This content is for general educational purposes and does not replace professional medical advice, diagnosis, or treatment. Consult an appropriately qualified healthcare professional for personal medical concerns. This article explains published guidance and does not provide a personal clinical assessment. Always consult qualified medical professionals for diagnosis and treatment of any health condition.

Frequently Asked Questions

What causes blood clots in the bladder in men?

Possible causes include an enlarged prostate, urinary infection, prostatitis, kidney or bladder stones, bladder cancer, bleeding from the kidneys or ureters, recent urinary procedures, trauma, blood thinning medicines, bleeding disorders, and radiation injury.

Are blood clots in the bladder dangerous?

They can be. The biggest immediate concern is clot retention, where clots block urine from leaving the bladder. Heavy ongoing bleeding can also cause significant blood loss.

What does clot retention feel like?

You may feel a strong need to urinate but pass little or no urine. The lower abdomen may become full, swollen, uncomfortable, or severely painful.

Can an enlarged prostate cause blood clots in urine?

Yes. BPH can cause visible hematuria in some men. However, visible blood should not automatically be blamed on BPH because other causes need consideration.

Can a UTI cause blood clots in urine?

A urinary infection can cause bleeding. Heavy bleeding can sometimes form clots, although large clots should prompt careful assessment for other possible causes as well.

Can kidney stones cause blood clots in the bladder?

Yes. Stones can injure urinary tissue and cause bleeding that travels into the bladder.

Does blood in urine mean bladder cancer?

No. Infection, stones, prostate problems, trauma, medicines, and other conditions can cause hematuria. Bladder cancer is one important cause that must be considered when visible blood is unexplained.

Can bladder cancer cause blood clots?

Yes. A bleeding bladder tumor can cause visible blood and sometimes clots. Visible hematuria can occur without pain.

Can blood thinners cause bladder blood clots?

Blood thinners can make urinary bleeding more noticeable or severe, but they should not automatically be treated as the only explanation. The underlying urinary source still needs assessment.

Should I stop my blood thinner if I see blood in urine?

Do not stop a prescribed anticoagulant or antiplatelet medicine on your own. Contact the clinician who manages the medicine or seek urgent care if bleeding is heavy.

Can drinking more water get rid of bladder blood clots?

Water does not dissolve an obstructing urinary clot. If you cannot urinate because of clots, seek urgent medical treatment rather than forcing large amounts of fluid.

How are bladder clots removed?

Medical treatment can include catheter drainage, bladder irrigation, and cystoscopic clot removal. The exact approach depends on the amount of clot, bleeding severity, and underlying cause.

What is continuous bladder irrigation?

Continuous bladder irrigation is a hospital treatment in which sterile fluid flows through a special urinary catheter to help prevent new clots from collecting while bleeding is managed.

What is cystoscopy?

Cystoscopy uses a thin camera passed through the urethra so a urologist can inspect the urethra and bladder. It can help find tumors, stones, bleeding points, inflammation, or other abnormalities.

Will a CT scan show the cause of blood in urine?

CT imaging can identify many kidney, ureter, stone, tumor, and structural causes. It does not replace cystoscopy in every situation because direct bladder inspection may still be needed.

Can radiation therapy cause bladder bleeding years later?

Yes. Pelvic radiation can cause delayed radiation cystitis and visible bleeding months or years later. New hematuria still needs assessment to rule out other causes.

Can bladder blood clots be prevented?

There is no single prevention method. Reducing recurrence depends on treating the cause, such as BPH, infection, stones, tobacco exposure, or complications after urinary treatment.

Does quitting smoking reduce bladder cancer risk?

Yes. Tobacco is a major modifiable bladder cancer risk factor, so stopping smoking is one of the most useful long term preventive steps.

When should a man see a urologist for blood in urine?

Visible unexplained blood should be medically evaluated even if it stops. Passing clots, repeated bleeding, urinary obstruction, older age, smoking history, or persistent blood after UTI treatment strengthens the need for urology assessment.

When should bladder blood clots be treated as an emergency?

Seek urgent care if you cannot urinate, develop severe lower abdominal pain or swelling, pass large repeated clots, have heavy ongoing bleeding, feel faint or very weak, or have fever and rapidly worsening urinary symptoms.