It started 3-4 days ago that he looses consciousness when he rests his head on pillow or any support while seating or sleeping. This lasts for few seconds and he gets normal again. Is it a need to worry? He is taking treatment and is doing well but still precaution is better than cure. He is 44 and having good diet.
I would march him round the doctors!
You say he is "taking treatment". What for? For his current condition? If the answer to this one is "yes", then I think you can trust his doctor to handle this. If he isn't been treated for this particular condition, you should get him straight to his doctor and ask for it to be investigated.
Treatment for what? I would say get help asap.