Trauma: This is the most common cause of rib fractures, resulting from direct blows to the chest, such as those sustained in motor vehicle accidents, falls, or assaults. The mechanism of injury and clinical presentation (e.g., chest pain, tenderness, and deformity) typically point towards this diagnosis.

Osteoporosis: Weakened bones due to osteoporosis can lead to rib fractures with minimal trauma or even spontaneously. This is more common in elderly patients or those with known osteoporosis.
Cancer: Metastatic disease to the bones, such as from breast, lung, or prostate cancer, can weaken the ribs and lead to pathological fractures.
Infection: Osteomyelitis or infections of the soft tissues around the ribs can lead to weakening and potential fracture.

Pulmonary Embolism: While not directly causing rib fractures, the pain from a pulmonary embolism can sometimes be mistaken for the pain associated with a rib fracture. Missing this diagnosis can be fatal.
Aortic Dissection: This is a life-threatening condition that can present with chest pain and might be confused with the pain pattern of a rib fracture, especially if the fracture is high in the thoracic cage.
Myocardial Infarction: Chest pain from a heart attack can sometimes be confused with the pain from a rib fracture, particularly if the patient has had recent trauma or strain that could plausibly have caused a fracture.

Fibrous Dysplasia: A rare condition where normal bone is replaced with fibrous tissue, leading to weakened bones that can fracture more easily.
Osteogenesis Imperfecta: A genetic disorder characterized by fragile bones that can fracture easily, often with minimal trauma.
Rib Tumors: Primary or metastatic tumors of the ribs can weaken the bone structure and lead to fractures. These are less common than other causes of rib fractures.