DEAR DOCTOR K: My mother is in her 70s. She fell a few weeks ago but seemed fine. Then she started to have double vision and some trouble with balance. A CT scan revealed a subdural hematoma. Her doctor advised bed rest and medication. Does this seem reasonable to you?

DEAR READER: A subdural hematoma (or hemorrhage) occurs when blood vessels near the surface of the brain burst. Blood collects beneath the dura mater. That’s the outermost layer of the brain’s protective covering.

Most subdural hemorrhages result from trauma to the head. In some cases, blood accumulates rapidly after injury, putting pressure on the brain and causing symptoms within just a few days. This is an “acute” subdural hemorrhage. It can cause loss of consciousness, paralysis or even death. It usually requires emergency surgery to drain the hematoma and control bleeding.

Other times, as in your mother’s case, bleeding may develop over weeks or even months. If symptoms begin more than two weeks after the head trauma, it’s called a “chronic” subdural hematoma. The symptoms your mother experienced – double vision and trouble with balance – are typical.

Some conditions can cause subdural hematomas that occur without any head trauma. Weakness in artery walls can cause them to start leaking blood. Certain types of cancer that spread to the brain’s protective covering also can cause bleeding.

Treatment is based on symptoms and the size of the hematoma. A doctor can determine the amount of bleeding from a computed tomography (CT) scan or a magnetic resonance imaging (MRI) scan. If your mother’s hematoma is small and has caused only minimal symptoms, then it’s reasonable for the doctor to recommend bed rest and medications. The medications should help control swelling and prevent seizures.