Lower lobe infiltrative changes in both lungs is a condition in which the patient shows a slightly higher density of lung tissue near the dorsal side of the lungs on a chest ct. The cause of this phenomenon is the presence of alveolar aggregates at the base of both lungs, resulting in the appearance of increased density shadows. Alveolar aggregates are usually caused by a large accumulation of secretions at the base of the lungs. The lower lobes of both lungs are also associated with gravity-related increases in surface tension and alveolar atrophy causing bilateral lower lobe dropout. Often, the accumulation can be relieved by changing position, such as turning and patting the back, and coughing out the sputum to allow the gravity-related alveolar atrophy to open up. If the patient is bilobar atelectasis and is bedridden for a long period of time, it means that the patient may have atelectasis; if it occurs in an obese patient, the bilobar atelectasis is relatively less severe, and it is up to the patient to determine whether the bilobar atelectasis is severe or not, depending on his or her own specific situation. If the lower lobes of both lungs are found to be affected, the patient should consult the doctor in time, complete the relevant examinations, make a clear diagnosis, and then take the appropriate treatment plan.