The probability of cancerous lung nodule shadows is usually based on the size of the nodule, so it is not a generalization. Patients with nodules that are small and less than about 5 mm in diameter usually have a lower probability of cancer, usually around 1%. Patients with nodules that are 10-20mm in diameter usually have a higher probability of cancer, usually between 35% and 65%. If the diameter of the nodule is large and larger than about 20mm, the probability of cancer is usually higher and may even reach about 80%. The specific probability of cancer depends on the patient’s own condition and physical fitness, and it is recommended that the patient go to the hospital for chest tumor markers, chest CT and other tests to determine the degree of the disease. If patients find nodules in the lungs, they should go to the hospital in time to avoid delaying the condition, which may cause irreversible damage.