Apart from your age, there is nothing on your profile; so we don't know very much about you.
However, you don't give enough information.What type of blood cell condition? That could be anything from sickle cells to Leukemia.
And in any case, it seems to be a problem outside your family. So leave it alone!
Anything can be healed. This site has healing spells. And I have had a little success with psychic healing (I'm sure others here have had more). But in all honesty, not everything will be or even should be healed.
Of course I agree with those who say your friend's grandfather needs a doctor. Modern medicine is a great thing.
However I can't agree to the idea of a doctor and not magic as though the two were contradictory.
In a perfect world magic and faith might work along side the efforts of the medical community tackling the problem from the spiritual and material worlds at the same time.
The real question is does the grandfather even want the kind of help he could find here? Or is he closed to magic? Or is he simply ready to move on beyond this life?
Is the real need for someone (like you) to come along side your friend as his grandfather goes through this? Sometimes a loved one's decline and eventual passing away can be harder and more frightening for those who will be left behind than the actual person. And you don't want to watch your friend hurting over his grandfather.
At such times being there and caring can be more helpful than offering solutions. We just need a friend to love us.
If the grandfather actually is asking for help, you should ask again with that made clear. :) Or better yet, have him post something.