If someone has lung cancer, will they cough up blood eventually?

Not necessarily: Coughing up blood ornhemoptysis when associated with lung cancer implies a tumor in one of the major airways usually. More distally located tumors can hide from detection longer since they may have no symptoms. Most patients that i can help as a surgeon have early stage disease, no symptoms, and their cancer was discovered because of something completely unrelated but warranted a chest x-ray.