This achievement is very similar to the achievement "Heal Up" in Halo 3: ODST, which also requires the player to use a Health Pack. The symbol of both achievements uses a medical symbol.
Players will at some point in campaign get wounded, specifically, the player will have low health in the campaign level Exodus, so unless the player doesn't care about his/her health, the player will acquire a health pack.
The achievement could be a possible reference to the song, "Doctor! Doctor!" by the Thompson Twins.