How to handle a team member when his efficiency looses due to his family or personal issues?

I think you can give him/her some time off to try resolve his/her issues and come back with freshness.

If personal problem cannot solve from his side, at least ask him take a trip of his favorite place by giving him some time off and come back freshly.

Try support or advise him in personal issues to resolve and be with him in his needy hour so that not to lose his mental strength thereby effects on his work efficiency.

There may be many other approaches but if we have knowledge of the issue, can better help him the right way to come back to his original efficient way of working as a team member.

You can't fix the personal issue.  If the person is willing to tell you what it is, you should offer what help you can.

What you can do is give them some space to fix the issue themselves.  Find out what they need from you.  A good example happened to a friend of mine.  Her mother died, not old, after a short illness.  They were close and she was distraught.  Her boss said, "Go home.  Take at least a week off.  Don't worry about your clients.  If you need to more time, just tell me.  If you want to come back part time for a while, just tell me.  Your job is waiting for you when you're ready to come back to it."  This gave her the confidence and security she needed, and she was back at work and performing as usual shortly afterwards.

The point is that the boss gave the one thing he could - peace of mind.  When your personal life is in turmoil (which happens to practically everybody at one time or another) the last thing you need is to have to worry about work.  Giving an employee that peace of mind will get them back to full speed faster than anything.

From time to time life will become more and more difficult  thats why some advices must be given to a team member at a rate of knowing his right problems because sometimes we can not separate work and issues whereas giving the team member a leave or a break mostly by his boss or head chef.

no employee should not mix the professional life with personal life, if any employee losses his efficiency other one should work with patients. And i do agree with the above answers too.