It's inevitable that during your adventure in SCUM, you're going to get hurt.
Stray bullets, a zombie (puppet) striking you, or falling from a high place are all ways in which you could lose health, leaving you very vulnerable and open to a single attack. This could kill you for good, causing you to restart, loot, and craft your items all over again.
Death means death in SCUM and you're very unlikely to find all of your resources again, so knowing how to heal yourself is vital to survival.
Most of the time, you'll want to use a clean rag to start the healing process since it's the item that mainly heals everything. You can also use emergency bandages, which can be found at looting spots.
You should heal naturally as long as you're looking after yourself by having a healthy diet and not eating or consuming negative foods, such as zombie remains.
You'll want to make sure that you stay well fed and hydrated because malnutrition and other illnesses can cause your character to get sick, refrain from healing, or get worse. You should also avoid having too much sugar since it can negatively affect your healing process.
Finding out what's wrong with you
Sometimes, you'll just randomly be sick and unable to understand what's wrong. There's an easy way to diagnose yourself, however, and it can all be accessed in the tab menu.
Hold the tab button and you'll open the metabolism menu, which also gives you the option to go to the bathroom, among other things. The top panel of the wheel will allow you to look at yourself and diagnose your problems, revealing what you need to heal.
This will reveal if you have a wound that's causing you to bleed, as well as other illnesses, which can be cured with particular methods and items.
In some situations, weapons or zombies can cause you to bleed out and lose health overtime.
The only way to cure a bleed is to use a clean rag to bandage yourself. You can get clean rags by cutting up clean clothing with a stone knife or any sharp weapon.
Dirty rags can't clean your wounds, so if you don't have clean clothes or rags on you, either search for some as soon as possible or prepare to die.