Deep inhalation without bottoming out may be caused by pulmonary fibrosis, right heart failure, lung cancer and other factors. 1. Pulmonary fibrosis: When pulmonary fibrosis occurs, there may be lattice-like changes in the lungs, leading to restrictive ventilation dysfunction, followed by inspiratory dysfunction, which may result in deep inhalation not reaching the bottom. 2. Right heart failure: right heart failure may cause a large amount of fluid to form in the chest cavity. If there is a large amount of fluid in the chest cavity, it may cause pressure on the lung tissues, making it difficult for gas to be inhaled into the lungs, resulting in the situation of not being able to inhale deeply to the end. 3. Lung cancer: when there are tumor cells growing in the lungs, it may cause pressure on the trachea and alveoli, so that the trachea and alveoli are in the state of occlusion, and when inhaling, it is difficult for the gas to pass through the occluded part, and it may also result in the situation of not being able to breathe deeply to the bottom. Deep inhalation can also be seen in other causes such as pneumonia, pleural effusion, etc., should consult a doctor in time, under the guidance of the doctor to improve the chest CT, echocardiography, MRI and other tests, to clarify the cause of the disease, and active treatment.