About Physiatry

Hypoxic Brain Injury

Condition: Hypoxic brain injury (HBI) occurs when the brain does not get enough oxygen, which causes brain cells to die.

Background: HBI can happen if blood flow to the brain is stopped or if there isn’t enough oxygen in the blood. Things that stop blood flow to the brain include blood loss from an injury or heart failure. Lack of oxygen in the blood can be caused by anything that stops a person from breathing or from carbon monoxide (CO) poisoning, where CO takes the place of oxygen in the blood.     

History and Symptoms: The symptoms of HBI depend on how long the brain has not had oxygen. There may be changes in behavior or thinking, or the person may lose consciousness. After becoming conscious, a person may still have other problems with behavior, thinking, vision, and movement. Some people have seizures.       

Physical Exam: The doctor will do tests to see how well the brain is working. If the person is conscious, can he answer questions, follow directions, move and see things normally? In both conscious and unconscious patients, the doctor will also test check reflexes, muscle tone, and response to a pinprick or other stimuli.     

Diagnostic Process: CT and MRI scans can show where and how much damage there is. Blood tests can help show what caused the HBI. Tests of vision, verbal and motor responses, and thinking will show how severe the injury is.

Rehab Management: The first step in treatment is to get oxygen to the brain and treat whatever injury caused the problem. Rehab then depends on the kinds of problems that remain. A combination of drugs and physical therapy may be needed, and the patient will also have to learn to adapt to physical and mental changes.   

Other Resources for Patients and Families: Support groups and counseling may help patients and families learn how to cope with changes. Organizations such as the Brain Injury Association of America may help. 

For Patients and Families:

View all Conditions & Treatments
Learn more about Physiatry

Find a Physician


Read the full PM&R Knowledge NOW® article at:

PM&R Knowledge NOW® Authors Needed

Participate in the development of PM&R Knowledge NOW® by applying to be an author of a 1,700-word summary of a clinical topic.

View a list of available topics and learn more about how to apply. Volunteering your time and expertise to is a great way to get published and recognized among your peers as a participant in this ground-breaking initiative!