Acute Injuries:
If you have just fallen or were a victim of a physical trauma, it is best to consult with a GP to rule out the possibility of a fracture or any damages to the major organs. Otherwise you can go see your physiotherapist after a few days to a week.
In the first few days after an acute injury (i.e.: sprains, tendinitis, muscle strains, etc), there would be too much inflammation that there is not much your physiotherapist can do. Almost any mobilization or maneuvers might make it worst since the inflammation still has not settled down. It is best to apply ice if it is inflamed and let your body rest properly!
Chronic Injuries:
In general, chronic conditions do take longer to recuperate. The reason being, the body has a tendency to compensate for weaknesses in any articulation. An example would be people with knee pain who have a tendency to put more weight on their other leg and their body would most often shift towards to other side alleviate pressure on the painful knee. It would for sure decrease the pain at the knee, but this puts excess stress on the back and on the pelvis over time. The longer you wait, the more damage is dealt to the body with or without your awareness since your body becomes so accustomed to these deformations.