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Coughing up blood (blood in phlegm)

Coughing up blood can have lots of possible causes. It could be something serious so it's important to get it checked.

Causes of coughing up blood

Common causes of coughing up blood include:

Sometimes coughing up blood can be a sign of something more serious like a blood clot or lung cancer.

It's important to get it checked out as soon as possible.

Urgent advice: Ask for an urgent GP appointment or get help from NHS 111 if:

  • you've coughed up a few small spots, flecks or streaks of blood, or noticed blood in your phlegm or handkerchief

You can call 111 or get help from 111 online.

Immediate action required: Call 999 or go to A&E immediately if:

  • you're coughing up more than just a few spots or streaks of blood
  • you're coughing up blood and finding it hard to breathe, have a very fast heartbeat or have pain in your chest or upper back

These symptoms could be a sign of a more serious problem like a blood clot in the lungs (pulmonary embolism).

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Page last reviewed: 29 October 2021
Next review due: 29 October 2024