Recovery after Acquired Brain Injury (ABI) may be affected by pre-existing (or pre-morbid) health issues or by injuries to other parts of the body (co-morbidities) that occurred at the same time.
Pre-existing health issues may include chronic medical conditions (e.g. diabetes, heart disease, mental health disorders, epilepsy etc.) and problems such as alcohol or substance misuse. These need to be identified 
early and management requires attention to such matters as:
- Safe administration of medicines to those with cognitive difficulties, behavioural difficulties or dysphagia.
- Provision of advice and support regarding nutrition, exercise and safety.
- Maintenance of contact with relevant medical and other health professionals.
Other injuries occurring at the same time as ABI are not uncommon, particularly in cases of trauma. Thus initial management must ensure detection of fractures, spinal cord damage and internal injuries of the chest or abdomen. These need to be attended to concurrently with treatment of the brain injury and may complicate the rehabilitation process.