I know this system won’t be implemented before a major combat overhaul (and it shouldn’t) as it would make the game too frustrating to play, but I think a more indepth health, damage and healing system would help make the game feel a bit more survival-ish, giving specific uses to things already in the game (like poultices, bandages, etc.), having to take care of wounds, the things you eat, and how you interact with nature and being a bit punished if you don’t. I should note I'm taking a lot of inspiration on Terrafirmacraft+, Project Zomboid, and The Long Dark's damage system (having played the last two myself).
Types of damage
Some of these are already in the game (blunt damage and piercing damage mentioned under throwing stones and arrows respectively).
Slashing damage
Caused by swords, axes, bears.
Produces exposed wounds.
Piercing damage
Caused by arrows and wolves.
Produces exposed wounds.
Blunt damage
Caused by fall damage and bighorn sheep ramming.
Produces sprains or fractures.
Starving damage
Caused by depleting the hunger bar.
Produces stomach ulcers and malnutrition if suffered over a long period of time.
Conditions
Exposed wounds
Caused by slashing and piercing damage.
Will decrease player’s health while exposed (not bandaged).
Has a chance to bleed (causing more damage and extending its healing time).
Will heal on its own after some time*.
Bandages or stitches (deep wounds) can be used to heal it faster.
Can become infected, after which it won’t heal until the infection is treated.
Infected wounds
Caused by keeping dirty bandages on the wound.
Will extend the wound’s healing time.
Won’t heal on its own.
If left exposed or kept with dirty bandages it will slowly start dealing damage.
Disinfecting the wound, and/or using certain antibacterial herbal infusions and poultices will help it heal the infection.
Sprain
Caused by a big amount of blunt damage.
Will slightly slow players movement until healed.
Will heal on its own after some time*.
Splints or casts can be used to heal faster.
Fracture
Caused by a huge amount of blunt damage.
Will slow players movement or tool usage considerably.
If present on the off-hand it will inhabilitate it.
Will heal on its own after a long time*.
Can be healed faster by using splints or casts.
Burns
Caused by fire, lava, and by being struck by lightning.
Will decrease player’s health while exposed (not bandaged).
Will heal on its own after a long time*.
Higher chance of becoming infected.
Disinfecting the wound, and/or using certain poultices (with honey or aloe vera**) will help it heal faster.
Stomach ulcer
Caused by a long time of starving damage.
Will decrease player’s health each time food is consumed.
Won’t heal on its own.
Can be treated using certain herbal infusions.
Food poisoning
Caused by eating rotting food, or (sometimes) bushmeat.
Food will provide slightly less nutrition.
Will heal on its own after a short while*.
Can be treated using certain antibacterial and other herbal infusions.
Parasites
Caused by eating rotting food, or (sometimes) bushmeat.
Food will provide a lot less nutrition.
Will heal on its own after a long while*.
Can be treated using certain antiparasitic herbal infusions.
Malnutrition
Caused by a habit of continuous starving damage.
Will slightly slow players movement or tool usage.
Won’t solve on its own.
Can be treated by keeping the hunger bar over a threshold consistently and by sleeping.
Common cold
Caused by a very long time of being exposed to rain and low temperatures.
Will slightly slow players movement or tool usage.
Will heal on its own after some time*.
Can be treated using certain herbal infusions.
Immunity can be developed after continuous exposure.
*The healing time might need to be tweaked to make it feel fair and not just another annoyance.
**Adding aloe vera as a plant would be nice to compliment this mechanic.
Medicine/Treatment
Along with this, some new items would be added to help counteract the negative traits some conditions give, or get rid of them full on, giving specific uses to bandages and herb-specific poultices (more below).
Stitching
Can be used to help deep wounds heal faster.
Bandages
Will stop damage and help with wound healing.
Will stop bleeding.
Bandages can be sterilized using aqua vitae.
Will become dirty after a while.
Bleeding wounds will dirty bandages faster.
If dirty bandages are applied or kept on wounds for long periods of times it will become infected and take longer to heal.
Splint/Cast
Can be used to help sprains or fractures heal faster.
Will reduce the movement and tool usage penalty of sprains and fractures.
Herbal Infusions + Poultices
Can be used to help with infections, stomach ulcers, food poisoning, parasites, bleeding, or the common cold depending on the type of infusion. (Some of these might not be backed by empirical evidence, just listing some of the properties I found of plants already in the game an example).
Health Tab
Along with this mechanic, a new tab on the player UI to see current conditions and an option to treat them would be added.
This is just a post compiling mechanics I've seen in other games I've played and thought might add some depth to the game once the combat mechanic is expanded upon. If you're interested or not feel free to leave some feedback as it's always appreciated :).