רְפָאֵנוּ ה' וְנֵרָפֵא
"Cure us, Oh God, so we will be cured..."
In this berakha we acknowledge that God is the ultimate healer. When we are sick, we assert, our cure ultimately comes from Him.
This Berakha, and the subject of being sick/being cured is a great example of the complex dynamics between man's freedom of choice and God's intervention in our lives.
First, in the way a disease is acquired. Many times illness is a consequence of our wrong choices. If we make an habit of eating the wrong foods, or if we don't take care of our health, sickness might be directly or indirectly our own making. The Rabbis expressed this idea in TB Ketubot 30a: הכל בידי שמים חוץ מצינים פחים "Everything is in God's hand, except colds and insolation". In other words, if I willingly expose myself too much to cold or too much to heat, I cannot expect HaShem to protect me from my bad choices. On the other hand, certain diseases (perhaps most) are not a consequence of our behavior, but an adversity out of our control. And many times it is impossible (and useless) to assess where the blame should be placed. In any case, we pray to HaShem to help us and to remove from us all illness, pains and wounds.
We must do all in our power to avoid being sick. And we must do all in our power to get cured. Nevertheless, we pray and beseech God to protect us from all illness, to heal our pain, to cure our wounds and to prolong our lives. We recognize Him as the ultimate healer. He has the final say.