The short answer
Soaking through a pad or tampon every hour for several hours in a row, or passing clots the size of a quarter or larger, means going to an emergency department, and so does any bleeding with dizziness, fainting, breathlessness or chest pain. Bleeding after menopause, between periods or after sex is a same-day call. Any bleeding that is new for your body is worth reporting.
CDC counts changing a pad or tampon in under 2 hours, or clots the size of a quarter or larger, as heavy menstrual bleeding. Soaking one every hour for several hours is an emergency.
Bleeding after menopause, between periods, or after sex should be raised with your care team the same day.
Bleeding paired with dizziness, fainting, breathlessness or chest pain means going to an emergency department.
Any bleeding that is new for your body is worth reporting, including blood in urine or flecks in phlegm.
On this page
Choose how you want to read this
The whole article, with every detail and caution.
This page is for anyone with unusual bleeding who wonders what it could mean. It lists when to get emergency or same-day care, then explains what bleeding from each part of the body can point to and how it is checked.
Go to an emergency department now if
- You soak through a pad or tampon every hour for several hours in a row, or pass clots the size of a quarter or larger.
- You vomit blood, or material that looks like coffee grounds.
- Your stools are black and tarry, or the toilet fills with red blood and clots.
- You cough up more than a few streaks of blood.
- Bleeding comes with fainting, dizziness on standing, breathlessness, or chest pain.
- Bleeding will not stop with 10 minutes of firm pressure.
Call the same day for
- Any vaginal bleeding after menopause, even one spot, even once.
- Blood in urine, visible or reported on a test.
- Bleeding after sex, or between periods when that is new for you.
- Petechiae, bleeding gums, or repeated nosebleeds.
- Flecks of blood in phlegm lasting more than a few days.
Write down the date, the amount, what you were doing, and any medicine you take that thins blood. That record is more useful to the clinic than a general description.
Bleeding is a location clue first
When bleeding turns out to be the first sign of a cancer, the site of the bleeding usually points at the organ. That is why the first question a clinician asks is not "how much" but "where from," and the second is "is this new for you."
Most unusual bleeding is not cancer. Other causes, such as hemorrhoids, infections and medicines that thin the blood, are more common. But bleeding is worth checking because it can be an early sign of some cancers.
Bleeding after menopause
Any vaginal bleeding after periods have stopped needs to be checked. NCI says irregular vaginal bleeding is the most common first sign of endometrial cancer. It usually appears early, which is why most people are diagnosed at stage I, when the cancer is highly curable.
Most bleeding after menopause is not cancer. Still, your care team decides which tests you need. Do not decide by yourself that a small amount does not matter.
One group should not wait. NCI says people who take tamoxifen for breast cancer and have abnormal uterine bleeding should have follow-up examinations and a biopsy of the uterine lining. Tamoxifen carries an FDA boxed warning about an increased risk of uterine cancer.
Bleeding between periods or after sex
Vaginal bleeding, bleeding after intercourse, unusual discharge, pelvic pain, and pain during sex are the listed possible signs of cervical cancer. Early cervical cancer often causes none of them.
The evaluation is a pelvic examination, cervical cytology (a Pap smear), HPV testing, and colposcopy with biopsy if anything looks abnormal. Endocervical curettage, a gentle scraping, samples the canal of the cervix.
NCI says cervical cancer is diagnosed most often in women aged 35 to 44.
Blood in the urine
NCI says bladder cancer typically presents with hematuria, blood in the urine, either visible or found only on a test. Less often it causes frequent urination, needing to pass urine at night, or burning. Those symptoms are more common with carcinoma in situ (early cancer in the bladder lining).
Blood in the urine is a reason to be checked even if it stops on its own. NCI calls cystoscopy, a camera passed into the bladder, the most useful test. Imaging such as CT urography may also be used to look at the upper urinary tract.
Rectal bleeding and blood in stool
Bright red blood on the paper is often from hemorrhoids, but bleeding from the bowel can also have a more serious cause. Tell your care team about any blood in your stool, a change in bowel habits lasting weeks, or black, tarry stool. Black, tarry stool can mean bleeding higher up, and it is on the emergency list above. Your team may order tests such as a colonoscopy to find the source.
Bruising, tiny red dots, and bleeding gums
Tiny red or purple spots on the skin (petechiae), bruises with no injury, bleeding gums and nosebleeds that keep coming back can mean the blood is not clotting well. Call your care team the same day. A simple blood count is often the first test.
Coughing up blood
Coughing up blood is listed by NCI among the symptoms people with lung cancer may have. It can also come from other causes, such as a chest infection. Coughing up blood of any amount needs a call to your doctor right away. Call 911 or go to an emergency department if you cough up more than a few streaks, or if it comes with trouble breathing, chest pain or feeling faint.
Related pages
A Symptom Is Not a Diagnosis, What Symptoms Should I Call My Oncology Team About Today?, and Biopsy.
Sources
- https://www.cdc.gov/female-blood-disorders/about/heavy-menstrual-bleeding.html
- https://www.cancer.gov/types/uterine/hp/endometrial-treatment-pdq
- https://www.cancer.gov/types/cervical/hp/cervical-treatment-pdq
- https://www.cancer.gov/types/bladder/hp/bladder-treatment-pdq
- https://www.cancer.gov/types/lung/hp/non-small-cell-lung-treatment-pdq
Common questions
When is bleeding an emergency?
Call 911 or go to an emergency department if bleeding will not stop, you soak through a pad or tampon every hour for several hours in a row, or you pass clots the size of a quarter or larger. The same applies if you vomit blood or coffee-ground material, your stools are black and tarry, the toilet water turns red with large clots, or you cough up more than a few spots or streaks of blood. Do not drive yourself.
Does it matter what else I feel at the same time?
Yes. Bleeding that comes with dizziness, fainting, breathlessness or chest pain needs emergency care whatever the amount. How fast you need help depends on where the bleeding is coming from and how much there is.
Which bleeding is a same-day call rather than 911?
Blood in your urine, bleeding after menopause, bleeding between periods or after sex, and flecks of blood in phlegm. Pinpoint red spots that do not fade, bleeding gums and nosebleeds are also same-day calls to your care team.
What if my bleeding is not on either list?
Any bleeding that is new for your body is worth reporting. Keep a written record of the dates, how severe it was, and how you responded to any medication. Written records help your care team give you precise care.
What support is there while I wait for answers?
Confirm the after-hours phone numbers for your care team, and write down your top priorities before your clinic appointment. Oncology social workers, financial navigators and support groups cover the physical, emotional and practical side. Endless online searching tends to raise anxiety rather than settle it.
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Written by: Cancer ExplainedSources last checked: 2026-10-02 what this meansLast updated: 2026-10-02Next planned review: 2027-08-03
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Cancer Explained does not originate medical claims. Every page restates guidance already published by the National Cancer Institute, the CDC, the USPSTF and the FDA, in plain language, with the source cited so you can check the original yourself. AI does the translating and organizing; automated checks test claims, citations, clarity and safety before anything publishes, and this is translation and navigation, not clinical judgment. Nothing here is personal medical advice, and no page can account for your particular situation.
Editorial status: Source checked — This page was written with AI assistance and then compared with the sources listed on it, looking for statements those sources do not back up. That check is not a sentence-by-sentence record and can miss errors. It is not a medical review, and it does not confirm the page is complete or right for your situation.
Human medical review: not completed. Pages here are not signed off by a clinician before they publish. That is not an oversight we are quietly working around: we restate published guidance and cite it, so the authority belongs to the source rather than to us, and every page names where its claims come from — you can verify us instead of trusting us. Where a volunteer clinician has reviewed a page, their name and credentials appear on it; where no name appears, no clinician has checked it. We are glad to have reviewers and are recruiting them, and we do not hold pages back waiting for one. Use this site to understand your situation and to ask better questions of the people treating you.
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