Can a jehovahs witness have a blood transfusion if its a matter of life and death?

Depends: Most jehovah's witnesses will not accept blood even in a life threatening situation. Others will accept some blood products. Hemoglobin counts can be increased before surgery by medicines, use blood-sparing surgical techniques and donation of own blood (autologous) before surgery may be options. Bottom line: legally, competent adults can refuse transfusions even if it causes death.

Yes: There are components that any jw can accept. And a jw can accept a blood transfusion any time, recognizing they will no longer be a member or allowed to be friends with members. Many jw's oppose the blood policy anonymously though they'll also be disfellowshipped if caught; see http://www.Ajwrb.Org/ i greatly admire these folks' courage.