Because there are relatively few pain receptors in the lungs, lung cancer is not associated with any pain at first, and the first symptoms of pain appear only relatively late. Many times, the patient does not even know that he or she is ill, but a chest CT or x-ray performed for another reason reveals that there is a problem. A characteristic symptom of lung cancer is a dry cough that does not want to go away. In smokers, the nature of the cough has changed. Bloody sputum is also common in lung cancer, and recurrent pneumonia occurs with a prolonged recovery time. Bloody sputum unfortunately suggests that the tumor has already reached the airways, so you should see a doctor immediately. The amount of blood can be very minimal, but the symptom should be taken seriously nonetheless. A quarter of patients experience unpleasant, persistent chest pain. It can indicate lung cancer if someone’s voice becomes hoarse, and there is a constant feeling of tiredness and weakness. The more advanced the disease, the more characteristic the symptoms. An example is pain in the shoulder area, which is caused by suppressed nerves due to the growth of the tumor.