Symptoms of a slow brain bleed, called a subdural hematoma, can include dizziness, change in behavior, confusion and headaches, WebMD notes. In very slow growing hematomas, a person may not exhibit symptoms for two weeks.
Other symptoms include nausea, vomiting, excessive drowsiness, apathy, seizures and weakness. People with a subdural hematoma can go from being conscious to becoming comatose immediately or unconsciousness several days after the head injury, WebMD warns.
A subdural hematoma is generally caused by a head injury, such as a fall or car accident, WebMD says. The blood vessels that run along the surface of the brain are torn due to the sudden blow to the head. The bleeding is under the skull, outside of the brain. People who take blood thinners or have a bleeding disorder are also more likely to develop a subdural hematoma by even a minor injury.
Depending on the severity of the hematoma, there are a number of different treatment options, from watching and waiting to brain surgery. In smaller bleeds with mild symptoms, doctors may decide to just observe the patient and perform multiple head imaging tests to see if the hematoma is improving. More severe injuries require surgery to reduce pressure on the patient's brain, WebMD states.