Ground glass nodules are seen in the left upper lobe of the lung and are a proprietary imaging term. It may be due to lung infection, interstitial lung disease, or lung cancer. 1. Lung infection: Lungs can be infected due to bacterial inflammation, viral infection, or Mycobacterium tuberculosis infection, which can lead to infectious lesions in the lungs, presenting as ground-glass nodule-like changes. 2. Interstitial lung disease: Interstitial lung disease can be caused when the lesion involves the pulmonary blood vessels, bronchial tubes and other parts of the lung. Ground-glass nodules may also appear in the lungs in the early stage. 3. Lung cancer: some patients with lung cancer can see unclearly demarcated glassy foci in their lungs, and their edges are usually rough, which can be presented as burr sign, and pathological biopsy is needed to confirm the diagnosis. Ground-glass nodules in lungs can also be seen in other diseases, and it is suggested that patients should consult doctors in time to avoid delaying their condition.