6. Bloody Phlegm

Seeing blood in your cough or phlegm, regardless of how little is never a good sign. Lung cancer patients will often see tiny spots of rust-colored blood when they cough or spit, along with other symptoms such as shortness of breath and chest pain.

Even if bloody cough isn’t as a result of lung cancer, it is most likely caused by some other serious underlying condition, therefore it is always best to get checked out by a doctor.