How long it takes for a small nodule to develop into lung cancer depends on the size and nature of the nodule, which is usually about 1 year for short nodules and about 3 years for long ones. Lung nodules are divided into three cases: ground glass nodules, partially solid nodules and solid nodules, among which partially solid nodules are the most malignant and most likely to develop into lung cancer, while ground glass nodules and solid nodules should also be alerted to the occurrence of lung cancer if they are larger than 8mm. The development of this nodule into lung cancer usually takes about 1 year, which requires high attention. High-resolution CT of the chest and enhanced CT of the chest can detect early whether the nodule is accompanied by short burr, lobulated, pleural depression sign and other lung cancer changes, some elderly people progress more slowly and may develop into lung cancer only in 2-3 years, so do not take it lightly.