The main reasons that cause pain when inhaling even after a fall on the chest include the following: 1. It is possible that a fall on the chest leads to rib fractures, which in turn cause pain when inhaling. The bone continuity of the ribs is damaged due to trauma, etc., and the fractured ends of the ribs are displaced during inspiration with the contraction of the intercostal muscles, thus causing pain. The diagnosis can be confirmed by performing chest X-ray or chest CT examination, etc. 2. Pain caused by traumatic injury resulting in strain on the soft tissue of the chest muscles. Trauma leads to edema, congestion and swelling of the chest muscles, and during inspiration, the intercostal muscles need to contract, and the local swollen tissues will aggravate the pain. If there is no fracture on chest X-ray or chest CT examination, the diagnosis of soft tissue strain can be confirmed, and symptomatic treatment such as blood activation can be administered.