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What to do if…
you cough up blood or see blood in your mucus

Produced and maintained by PanicStation.org Published: Last reviewed: Editorial policy USA guide

Short answer

Call 911 now if you are coughing up a lot of blood, the bleeding will not stop, you have severe shortness of breath, or you do not feel able to get to emergency care safely. Go to the ER now for more than a few teaspoons of blood or for chest pain, shortness of breath, dizziness, lightheadedness, or fever; call 911 instead if you need emergency assistance. Even if it was only a small streak and you otherwise feel stable, contact a healthcare professional promptly.

Do not do these things

  • Do not drive yourself if you feel faint, dizzy, short of breath, or very unwell.
  • Do not assume new or repeated blood-streaked mucus is only irritation.
  • Do not change or stop prescribed medicines, including blood thinners, unless a healthcare professional tells you to.
  • Do not delay care to test whether exercise or harder coughing makes the bleeding worse.
  • Do not spend time trying to diagnose the cause yourself.

What to do now

  1. Check for emergency signs.
    Call 911 now if:

    • you are coughing up a lot of blood
    • the bleeding will not stop
    • you have severe shortness of breath
    • you feel faint, rapidly worse, or unable to get to emergency care safely

    Go to the ER now, or call 911 instead if you need emergency assistance, if:

    • you have coughed up more than a few teaspoons of blood
    • you have chest pain, shortness of breath, dizziness, lightheadedness, or fever
  2. Sit down and note what you can see.
    Avoid exertion while you arrange care. If a tissue or container is already available, use it so you can tell the healthcare professional whether it was a streak, a larger amount, or repeated bleeding.

  3. Check whether the blood may be coming from somewhere else.
    Look for a nosebleed or bleeding from your gums or mouth. If you are vomiting blood, or the material looks dark and coffee-ground-like, go to the ER now or call 911 if you need emergency assistance.

  4. Contact care promptly even if it was a small streak.
    If you feel stable and the amount was small, contact your primary care office, urgent care, or another healthcare professional promptly. Go to the ER if the bleeding continues, increases, or you develop warning symptoms.

  5. Share the details that help with triage.
    Note when it started, whether it happened once or repeatedly, the estimated amount, and the color. Mention fever, chest pain, shortness of breath, dizziness, recent illness, a recent nosebleed, and any blood-thinner medicine.

  6. Bring your medication information if you are being seen.
    Bring or show a list of medicines, especially blood thinners, along with allergies and important medical conditions. Ask someone else to drive if you do not feel safe to drive yourself.

What can wait

  • You do not need to work out the cause before contacting care.
  • You do not need to decide which tests or treatments you might need.
  • You do not need to finish work, chores, or errands before seeking help.

Important reassurance

Seeing blood can feel frightening. A small streak can sometimes happen after forceful coughing, but new or unexplained blood still deserves prompt medical advice. Focus on the amount, any warning signs, and the next safe step.

Scope note

These are first steps only. A healthcare professional may need to assess the cause and advise on any later tests or treatment.

Important note

This is general information, not medical advice or a diagnosis. If the bleeding is continuing, increasing, or hard to judge, or if you are becoming unwell, call 911 or go to the ER.

Additional Resources

About this guide

This guide was produced and is maintained by PanicStation.org using its published editorial process. Official and specialist sources are checked where relevant, and AI-assisted tools may be used for drafting, organisation, and consistency checks. The site operator remains responsible for publication, revision, and removal decisions.

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