An acute subdural hemorrhage develops over minutes to hours. If not diagnosed and treated promptly, it can cause severe brain injury and sometimes death.
A chronic subdural hemorrhage develops over many days to weeks. The symptoms may be subtle and develop so slowly that the person and family are not alarmed.
As is the case with any brain injury, symptoms can be slow to go away after treatment. Some symptoms may be permanent.
Occasionally, a subdural hematoma is small enough that you may not need surgery to remove the blood. The blood will be reabsorbed gradually by the body. This process may require a few months. But it is sometimes the safest treatment plan.