We're at the point where we barely think twice about any of this. As players we have a Pavlovian response to health items. The only thing triggering in our brains when we guzzle a crate full of pills is, "Ooh, health jackpot," when it should be, "Good heavens, my pancreas just melted." Somebody without a morality gland could let the pharmaceutical industry know that videogames are doing a terrific, daily job marketing its products as panacea.
Check With Your Doctor
Of course, games' obsession with medication has a lot to do with the way videogame health is portrayed. Generally, it's a linear bar of some sort, with no particular distinction made between types of pain or illness. Sometimes a game like Deus Ex will come along and differentiate between limbs, meaning if you're shot in the arm you need to direct a magical medical bag to that area; but Deus Ex was also a title in which you could briefly survive as just a bouncing head. The videogame hero never seems to just be feeling under the weather or suffering from a minor headache, or mostly OK but carrying a niggling shoulder injury. Credit needs to be given to Metal Gear Solid 4 here for recognizing back pain from prolonged crouching as a serious gameplay concern, but this breakthrough in medically-minded gaming is slightly undermined by one of the best cures being "Snake reads a girlie mag for a bit."
Health kits and other medical items are by no means new innovations in the field; Doom had them way back in 1993, and was certainly not the first. Regardless of who had the initial bright idea, health packs were everywhere in games through the mid-90s. They were symptomatic (every pun intended) of the transition away from ports of vicious arcade games in which a single hit was liable to end you. Characters in this era were flimsy folk, prone to falling dead at the merest hint of a touch from an enemy. Prior to the development of the health kit, games instead plied you with extra lives, a reward that couldn't heal your hero, but would give him another chance to leap back out of the grave.
Once developers realized that it wasn't actually necessary to replicate the brutal change-snatching design of the arcades, things began to change. This is why Braben and Bell's Elite, the 1984 space trading epic, had shields for the player's Cobra Mk III vessel. Those shields were health in all but name, and a further sign of how far forward that title cast its gaze.