What causes bloody phlegm?

Answer:
I have seen cases where bloody phlegm was a symptom of pneumonia. Strong coughing can cause the small blood capillaries to bust and the blood mix up with the phlegm.

The exact cause of this symptom is best investigated by a medical professional in order for a diagnosis to be made you should visit a doctor.
First answer by ID1206221782. Last edit by ApekillerXD. Contributor trust: 0 [recommend contributor recommended]. Question popularity: 2 [recommend question].