The possible condition of solid nodule in the left upper lung is tuberculosis, but it may also be inflammation of the lung, lung tumor, etc. 1. Tuberculosis: Secondary tuberculosis occurs in the apical posterior segment of the upper lobe of the lung or the apical segment of the lower lobe, and solid nodules in the left upper lung may be tuberculosis. If there are other clinical symptoms such as hemoptysis, further examination should be carried out. 2. Lung inflammation: Inflammation of the lungs usually causes solid lung nodules, but usually the size of the nodules is small, and the nodules will shrink significantly after using anti-inflammatory drugs. 3. Lung tumor: Lung tumors can appear in all parts of the lungs, and in the early stage, there may be small shadows, which may be hairy glass-like, and then there may be lobed or burr signs. If there is a solid nodule in the left upper lung, patients need to go to the hospital in time for a clear diagnosis, do not delay, so as not to cause the deterioration of the condition.