The short answer
Unusual bleeding — such as blood in the stool or urine, bleeding between periods, or easy bruising — can be a warning sign of some cancers. Most causes are not cancer, but unexplained bleeding should be checked.
Unusual or unexplained bleeding can be a warning sign of some cancers.
Blood in the stool or urine, or bleeding between periods, should always be checked.
Easy bruising or bleeding can be a sign of leukemia, which affects blood cells.
Coughing up blood or blood in vomit should be evaluated promptly.
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The full explanation.
The simple version
Bleeding that is unexpected or has no clear cause can be a warning sign of some cancers. Most bleeding comes from things that are not cancer, but because it can be a sign, unexplained bleeding should always be checked.
Bleeding to get checked
See a doctor for:
- Blood in the stool or black, tarry stools
- Blood in the urine
- Bleeding between periods or any bleeding after menopause
- Coughing up blood or blood in vomit
- Easy bruising or bleeding with no clear cause
What it can signal
Bleeding can be a sign of colorectal cancer (blood in stool), bladder or kidney cancer (blood in urine), and cervical or uterine cancer (abnormal vaginal bleeding). Easy bruising or bleeding can be a sign of leukemia, which affects the blood cells.
Blood in the stool or urine, and any bleeding after menopause, should always be checked.
When to see a doctor
Many causes of bleeding are not cancer — hemorrhoids, infections, ulcers, and some medicines all cause bleeding. Still, any unexplained bleeding should be evaluated by a doctor to find the cause.
Words to know
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Common questions
▸What kinds of bleeding should I check?
Get checked for blood in the stool or urine, bleeding between periods or after menopause, coughing up blood, blood in vomit, or unexplained easy bruising or bleeding.
▸Which cancers cause bleeding?
Bleeding can be a sign of many cancers, such as colorectal cancer (blood in stool), bladder or kidney cancer (blood in urine), and cervical or uterine cancer (abnormal vaginal bleeding). Easy bruising can be a sign of leukemia.
▸Is bleeding always cancer?
No. Bleeding often comes from non-cancer causes such as hemorrhoids, infections, ulcers, or medicines. But because it can signal cancer, unexplained bleeding should be checked.
▸When should I see a doctor?
See a doctor for any unexplained bleeding, blood in the stool or urine, bleeding between periods or after menopause, or easy bruising with no clear cause.
Questions to ask your doctor
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