Blood in Urine (Haematuria):
Causes, Diagnosis & Treatment
Seeing blood in your urine (haematuria) can be worrying, even if it happens only once. While many causes, such as urinary tract infections, kidney stones and an enlarged prostate, are not serious, blood in the urine can sometimes be an early sign of a more significant urinary tract condition. This guide explains the possible causes, investigations and treatment options, and when you should see a urologist.
What Is Blood in Urine?
Blood in the urine is known medically as haematuria. It is a symptom rather than a disease, meaning there are many possible underlying causes. Doctors generally classify haematuria into two main types:
Visible blood in the urine (gross haematuria)
The urine appears pink, red or brown because enough blood is present to be seen.
Visible blood in the urine should always be assessed, even if it occurs only once and disappears.
Microscopic blood in the urine
The urine appears normal, but a urine test detects small amounts of blood under the microscope.
Microscopic blood in the urine may be discovered during a health screening, insurance medical examination or investigation for another condition. Depending on your age, symptoms and medical history, further assessment may be recommended.
The amount of blood does not necessarily indicate how serious the underlying cause is. A small amount of bleeding can occasionally be associated with significant conditions, while heavy bleeding may sometimes be caused by a condition that is easily treated.
Even if blood in the urine occurs only once and then disappears, it should not be ignored. A single episode of visible blood in the urine may be the first sign of an underlying urinary tract condition that requires assessment.
Does Blood in Urine Always Mean Cancer?
No. Most people with blood in the urine do not have cancer, but it is important to identify the cause because early urinary tract cancers are often most treatable when detected promptly.
Many cases are caused by conditions such as:
- Urinary tract infections (UTIs)
- Kidney or ureteric stones
- An enlarged prostate (BPH)
- Vigorous exercise
- Certain medications, including blood thinners
Blood in the urine can also be an early sign of bladder cancer, kidney cancer or other urinary tract conditions. In some people, it may be the only symptom, particularly in the early stages.
Because it is not possible to determine the cause based on symptoms alone, unexplained blood in the urine should always be assessed by a doctor rather than assumed to be harmless.
Blood in Urine Without Pain
Painless blood in the urine should never be ignored. Although many causes are not serious, it can sometimes be the earliest sign of bladder cancer or another urinary tract condition.
Many people assume that if there is no pain, the bleeding is not serious. However, painless visible blood in the urine can sometimes be an early sign of conditions affecting the bladder or kidneys.
On the other hand, painful blood in the urine is more commonly associated with kidney stones or urinary tract infections.
Whether blood in the urine is painful or painless, the underlying cause cannot be determined without appropriate assessment.
Who Is at Higher Risk of a Serious Cause?
Not everyone has the same risk of a serious underlying condition. A more thorough assessment is often recommended for adults with blood in the urine who have one or more of the following risk factors:
- Age 40 years or older
- Current or previous smoking
- Visible blood in the urine without pain
- Recurrent episodes of blood in the urine
- Previous urinary tract cancers
- Long-term catheter use
- Occupational exposure to industrial chemicals or dyes
- Previous pelvic radiotherapy
- Persistent microscopic blood found on repeated urine tests
Even if you do not have these risk factors, unexplained blood in the urine should still be assessed.
When Should Blood in Urine Be Checked?
Visible blood in the urine should generally be assessed by a doctor, even if it occurs only once.
You should seek medical assessment if you notice:
- Visible blood in the urine
- Blood in the urine that keeps recurring
- Blood clots in the urine
- Blood in the urine together with urinary symptoms
- Blood in the urine with fever or chills
- Severe pain in the back, side or lower abdomen
- Difficulty passing urine
- Unexplained weight loss
Microscopic blood in the urine may also require further evaluation depending on your age, symptoms and risk factors.
Why Is There Blood in My Urine?
Blood in the urine can occur anywhere along the urinary tract, including the kidneys, ureters, bladder, prostate (in men) and urethra. While many causes are not serious, some require prompt diagnosis and treatment.
Below are some of the more common causes.
Kidney Stones
Kidney stones are one of the most common causes of blood in the urine. As a stone moves through the urinary tract, it can scratch the lining of the kidney or ureter, causing bleeding. Blood in the urine may be visible or detected only on a urine test.
In addition to blood in the urine, kidney stones often cause:
- Severe pain in the back or side (flank pain)
- Pain that may spread to the lower abdomen or groin
- Nausea or vomiting
- Pain when passing urine
- Frequent or urgent urination
Small stones may pass naturally, while larger stones may require treatment such as shockwave therapy (ESWL), ureteroscopy or percutaneous nephrolithotomy (PCNL).
Read more about Kidney Stones Treatment.
Urinary Tract Infection (UTI)
A urinary tract infection can irritate the lining of the bladder or urinary tract, causing blood to appear in the urine.
Symptoms may include:
- Burning or pain when passing urine
- Frequent urination
- A strong urge to urinate
- Cloudy or foul-smelling urine
- Lower abdominal discomfort
Most urinary tract infections improve with appropriate antibiotics. If blood in the urine persists after the infection has resolved, further assessment may be recommended.
Enlarged Prostate (Benign Prostatic Hyperplasia, BPH)
In men, an enlarged prostate can occasionally cause blood in the urine. This may occur because enlarged prostate tissue contains fragile blood vessels that can bleed, or because it affects normal urine flow.
Other symptoms may include:
- Weak urine stream
- Difficulty starting urination
- Frequent urination, especially at night
- A feeling that the bladder has not emptied completely
Treatment depends on the severity of symptoms and may include lifestyle measures, medication or minimally invasive procedures.
Read more about Enlarged Prostate (BPH).
Bladder Cancer
Blood in the urine is the most common symptom of bladder cancer. In many people, it is painless and may come and go, which can lead to delays in seeking medical attention.
Other symptoms may include:
- Frequent urination
- Pain when passing urine
- Urgency to urinate
- Pelvic discomfort (less common)
Although bladder cancer is less common than infections or kidney stones, it should be considered, particularly in older adults and those with risk factors such as smoking.
Kidney Cancer
Kidney cancer may also cause blood in the urine, although many people have no symptoms in the early stages.
When symptoms do occur, they may include:
- Blood in the urine
- Persistent pain in the side or back
- A lump in the abdomen or side (less common)
- Unexplained weight loss or fatigue
Many kidney tumours are discovered incidentally during scans performed for unrelated reasons, before symptoms develop.
Other Possible Causes
Less common causes of blood in the urine include:
- Vigorous exercise, particularly long-distance running
- Certain medications, including blood thinners
- Kidney inflammation (glomerulonephritis)
- Injury to the kidneys or urinary tract
- Some inherited kidney conditions
A medical assessment helps determine whether further investigation is needed.
How Do Doctors Find the Cause of Blood in the Urine?
The next step is to determine where the bleeding is coming from and why it has occurred.
Your urologist will consider factors such as:
- Your age
- Whether the blood is visible or microscopic
- Whether it is painful or painless
- Your smoking history
- Previous urinary tract infections or kidney stones
- Other urinary symptoms
- Your medical history and medications
Based on these findings, further tests may be recommended to identify the underlying cause.
Haematuria Investigation: How Is Blood in the Urine Investigated?
A urological assessment usually involves several steps.
1. Medical History and Physical Examination
Your urologist will ask about:
- When the blood first appeared
- Whether it is visible or detected only on a urine test
- Whether it occurs with pain, fever or urinary symptoms
- Previous kidney stones or urinary tract infections
- Smoking history
- Current medications, including blood thinners
- Any previous urinary tract conditions or surgery
A physical examination may also be performed if appropriate.
2. Urine Tests
A urine sample helps look for:
- Blood
- Signs of infection
- Protein
- Other abnormalities
In some situations, a urine culture may be performed to check for bacterial infection.
Your doctor may also recommend urine cytology, which examines urine for abnormal cells that may suggest certain urinary tract cancers.
3. Blood Tests
Blood tests may be recommended to assess:
- Kidney function
- Signs of infection
- Anaemia if significant bleeding has occurred
4. Imaging of the Urinary Tract
Imaging helps identify abnormalities involving the kidneys and ureters.
Depending on your symptoms, this may include:
- Ultrasound
- CT scan
- CT Urogram (when appropriate)
These tests can detect problems such as:
- Kidney stones
- Kidney tumours
- Urinary tract obstruction
- Other structural abnormalities
5. Flexible Cystoscopy
A flexible cystoscopy allows the urologist to examine the inside of the bladder and urethra using a thin flexible camera.
It is often recommended for adults with visible blood in the urine or when bladder abnormalities need to be excluded.
The procedure is usually performed using local anaesthetic gel and typically takes only a few minutes.
Read about Flexible Cystoscopy
Results from all investigations are considered together to determine the underlying cause and whether treatment is required.
Will Everyone Need Every Test?
No.
Not everyone requires every investigation.
The recommended tests depend on factors such as:
- Your age
- Whether the blood is visible or microscopic
- Whether bleeding is painful or painless
- Your symptoms
- Your medical history
- Your individual risk factors
Some people may require only urine tests and imaging, while others may also benefit from flexible cystoscopy or additional investigations.
Haematuria Treatment: How Is Blood in the Urine Treated?
Blood in the urine itself is a symptom. Treatment focuses on addressing the underlying condition causing the bleeding.
Once the cause has been identified, your urologist will recommend the most appropriate treatment. In some cases, no treatment is required, while others may benefit from medication or a procedure.
Treatment for Urinary Tract Infections
If a urinary tract infection is causing the bleeding, treatment usually involves antibiotics. Most people notice improvement once the infection has been treated.
If blood in the urine persists after the infection has cleared, further investigation may be recommended to exclude other underlying conditions.
Treatment for Kidney Stones
Small kidney stones may pass naturally with time, fluids and pain relief.
Larger stones or stones causing persistent pain, infection or blockage may require treatment such as:
- Shockwave lithotripsy (ESWL)
- Flexible ureteroscopy (URS)
- Percutaneous nephrolithotomy (PCNL) for larger or more complex stones
Read more about:
Treatment for an Enlarged Prostate (BPH)
If an enlarged prostate is contributing to blood in the urine, treatment depends on the severity of symptoms.
Options may include:
- Lifestyle measures
- Medication
- Minimally invasive procedures
- Surgery for selected patients
Treatment aims to improve urinary symptoms and reduce the risk of further complications.
Read more about:
Treatment for Bladder Cancer
If investigations identify bladder cancer, further treatment depends on the stage and grade of the tumour.
Management may include:
- Transurethral resection of bladder tumour (TURBT)
- Intravesical therapy
- Surgery
- Chemotherapy or immunotherapy in selected cases
Early diagnosis generally offers more treatment options.
Treatment for Kidney Cancer
Treatment depends on the size and stage of the kidney tumour, as well as your overall health.
Options may include:
- Active surveillance for selected small tumours
- Partial nephrectomy
- Radical nephrectomy
- Other treatments when appropriate
Many kidney cancers detected early can be treated successfully.
Can Blood in the Urine Go Away on Its Own?
Sometimes.
The bleeding may stop even though the underlying condition is still present.
For example, blood caused by a small kidney stone or a urinary tract infection may resolve as the condition improves. However, bleeding due to bladder cancer or other urinary tract conditions may also occur intermittently.
For this reason, visible blood in the urine should not be ignored simply because it has disappeared.
When Should You Seek Urgent Medical Attention?
You should seek prompt medical attention if you have blood in the urine together with:
- Heavy bleeding or large blood clots
- Difficulty passing urine or inability to urinate
- Severe pain in the back, side or lower abdomen
- Fever or chills suggesting an infection
- Dizziness, fainting or symptoms of significant blood loss
These symptoms may require urgent assessment and treatment.
When Should You See a Urologist?
You should consider arranging a urological assessment if you:
- Notice visible blood in your urine, even if it happens only once
- Have persistent microscopic blood found on urine testing
- Experience recurrent episodes of blood in the urine
- Have blood in the urine together with urinary symptoms
- Have risk factors such as smoking or a previous history of urinary tract disease
An assessment helps identify the underlying cause and determine whether further investigation or treatment is needed.
Can Blood in the Urine Be Prevented?
Not all causes of blood in the urine can be prevented. However, some simple measures may help reduce the risk of certain urinary tract conditions.
Stay well hydrated
Drinking enough water helps dilute the urine and may reduce the risk of kidney stones and some urinary tract infections.
Do not ignore urinary symptoms
Burning during urination, frequent urination or recurrent urinary tract infections should be assessed early to prevent complications.
Stop smoking
Smoking is the most important preventable risk factor for bladder cancer. Stopping smoking reduces the risk over time and provides many other health benefits.
Manage medical conditions
Conditions such as high blood pressure and diabetes can affect kidney health. Regular medical follow-up helps reduce the risk of kidney-related complications.
Attend follow-up appointments
If you have previously been treated for kidney stones, bladder cancer or another urinary tract condition, regular follow-up may help detect recurrence or complications early.
Frequently Asked Questions
Can blood in the urine come and go?
Yes.
Blood in the urine may appear once, disappear and return later. Even if the bleeding stops, the underlying cause may still be present. Visible blood in the urine should always be assessed, even if it only occurs once.
Why is there blood in my urine but no pain?
Blood in the urine without pain does not necessarily mean a serious condition, but it should not be ignored.
While painless bleeding can occur for several reasons, it may also be an early sign of bladder cancer or another urinary tract condition. A medical assessment helps determine the underlying cause.
Can kidney stones cause blood in the urine without pain?
Yes.
Some kidney stones cause only microscopic bleeding, while others may cause visible blood in the urine before significant pain develops. The amount of blood does not necessarily reflect the size of the stone.
Can an enlarged prostate cause blood in the urine?
Yes.
An enlarged prostate can occasionally cause blood in the urine because enlarged prostate tissue contains fragile blood vessels that may bleed. It is more commonly associated with urinary symptoms such as a weak urine stream, frequent urination and difficulty emptying the bladder.
Is blood in the urine always visible?
No.
Some people have microscopic blood in the urine, which can only be detected during a urine test. Although it cannot be seen, further assessment may still be recommended depending on your age, symptoms and medical history.
Can blood-thinning medication cause blood in the urine?
Blood-thinning medication may make bleeding more noticeable, but it does not necessarily explain why the bleeding occurred.
If you develop blood in the urine while taking blood-thinning medication, further assessment may still be needed to identify the underlying cause.
Is blood in the urine an emergency?
Not always.
However, you should seek prompt medical attention if you have blood in the urine together with:
- Difficulty passing urine
- Heavy bleeding or large blood clots
- Severe pain
- Fever or chills
- Dizziness or fainting
These symptoms may require urgent assessment.
Should I see a urologist if blood in the urine happened only once?
Yes.
Visible blood in the urine should be assessed even if it occurs only once or disappears on its own. Early assessment helps identify the underlying cause and determine whether any further investigation or treatment is needed.
Does dehydration cause blood in the urine?
Dehydration itself does not usually cause blood in the urine. However, it may increase the risk of kidney stones or urinary tract infections, which can lead to bleeding. Drinking enough water supports urinary tract health but does not replace medical assessment if blood is present.
Is microscopic blood in the urine serious?
Not always. Microscopic blood in the urine means blood cells are present but cannot be seen with the naked eye and are only detected on a urine test.
In some people, it may be temporary or related to a urinary tract infection, vigorous exercise or a small kidney stone. However, it can also be an early sign of conditions affecting the kidneys, bladder or urinary tract, including, in some cases, urinary tract cancer.
If microscopic blood in the urine persists, especially in adults over 40 or those with risk factors such as smoking, further assessment may be recommended to determine the underlying cause.
Can red urine always mean blood?
Patients often notice red, pink or brown urine before knowing it’s haematuria. Explain that some foods and medications can also change urine colour, but persistent or unexplained red urine should be assessed.
Concerned About Blood in Your Urine?
Blood in the urine should always be assessed to identify the underlying cause. A consultation allows your urologist to review your symptoms, arrange appropriate investigations if needed, and discuss the next steps based on your individual situation.