A lot of things can lead to brain injury. Problems may not always be physically obvious. Most often survivors are left struggling with "invisible" problems less likely experienced by other clients. Professional or friend or family member, if you are a carer these can equally affect you especially where there is lost awareness of the effects they have on you and others. Here are some examples of the types of problems associated with brain injury:-
Long-term memories of a life that was and little or none of the short-term memory needed to cope with life here and now
Difficulties "reading people"
Strong emotions and new and unexpected behaviour making survivors and those around them question who they've become and how much of the familiar self is still there.