Which of the following is a complication associated with fractures?

Shock is a serious complication that can occur following fractures, particularly in cases of significant trauma or injury. When a fracture happens, especially in areas such as the pelvis or femur, it can lead to substantial blood loss, either from the fracture site or associated soft tissue injuries. This significant blood loss can result in hypovolemic shock, where the body does not have enough blood volume to supply oxygen to the organs.

Moreover, the pain and stress associated with a fracture can also induce neurogenic shock due to the body's exaggerated response to pain. In both cases, prompt recognition and treatment of shock are critical to prevent further complications and support the patient's recovery.

In contrast, while hypoglycemia, dehydration, and allergic reactions may occur in various medical circumstances, they are not direct complications typically associated with fractures. They do not arise solely due to the fracture itself but rather relate to other factors such as pre-existing health conditions or reactions to medications or fluids given during treatment. Understanding shock as a potential complication underscores the importance of monitoring patients with fractures closely for any signs of circulatory instability.