Blood phlegm can be alarming, but isn’t usually serious if you’re young and healthy. However, it can also happen in older people, particularly those who smoke. Blood in phlegm is known as hemoptysis.
Blood in phlegm may mean that blood is may be from your lungs and is often the result of too much coughing or a lung infection.
If the blood contains food particles, is dark or looks like coffee grounds, it may be from the stomach or intestines. This needs immediate medical attention.
Blood with little or no sputum needs immediate medical attention.