1 Immediate swelling
As soon as a bone is broken the affected site swells right away. The area appears much bigger compared to the same area in the side of the body that wasn't affected.
2 Intense pain
When a bone is broken intense pain will be felt right away. The pain becomes more intense if you try to move the limbs in the affected area.
3 Sometimes a cracking sound is heard
Sometimes a person might hear the sound of the cracking of the bone as it breaks. This is more likely to happen with large bones.
4 Unable to move affected limbs
When a bone breaks a person feels intense pain whenever he tries to move the affected area. In most cases, the person loses some of his mobility instantly.
5 A person might experience shock
Some people experience a state of shock after breaking the bone. They might feel dizzy, imbalanced or unable to think properly. In rare cases, the person might faint.
6 Pain depends on fracture type
The type and the intensity of the fracture is one of the factors that affect the pain a person feels. Compound fractures might hurt much more. (See How to Stop Back Pain Fast?)
7 Pain stops with immobilization
When the affected area is immobilized, by putting on a cast for example, then the pain usually stops.
8 Sometimes a person might be able to move
In one kind of fracture, called impact fracture, the broken bones are forced to stick together as a result of the impact. In such a case, pain will be there but mobility might not be greatly impacted unless the person puts a load on the bone.
9 Half of the limb moving
If the fracture is severe the person might notice that only half of his limb moves inside his skin, whereas the other half remains motionless. This can happen when very big bones are broken like the femur bone. (See What does it feel like to lose a limb in an accident?)