An universal aspect to every living being is their health. No matter their occupation, race or affiliation, they can only take so many hits before they'll come running for a medic. That's where you come in! This guide seeks to arm you with the basics of medical, if you're an up-and-coming doctor, or an unlucky crewman.

The Fundamentals

If you've ever played on a ship before, you may have noticed the severely decreased amount of medical equipment compared to a station. You might not have medical equipment at all! There will be things outside of your control that will warrant a call for specialized aid. That's what medical ships are for.

Damage Types

In SS13, overall health works off a number influenced by four increasing damage values. If the combined sum of these values is over 100 (this varies with mood) you enter into critical condition, and if it goes over 200, death occurs. The most basic idea of medical is to keep this from happening and/or reduce these numbers to zero. You can achieve this with simple things like sutures and regenerative mesh, stocked in your standard first aid kits, but dedicated medical roles may have access to surgical tools and chemistry which allow to treat more damages and do it faster.

Oxygen Damage

You look for this one first, reflected in blue. Patients will start gasping for air. Lacking oxygen, low blood, being in a critical condition, heart attacks and organ damage can all cause suffocation. While it doesn't have the side effects that other damage types might, it is still very deadly.

Drag the damn patient to a place with oxygen. Or put internals on them. You can put it at a higher pressure if they struggle to breathe.
If damage is above 100, you can click on the patient with an empty hand to apply CPR. You can spam click this.
Chemicals can prevent or heal Oxygen Damage.

Brute Damage

This is the most common source of damage, reflected in red. It is visible and specific to each limb. Getting hit by sharp or blunt things, struck by fauna or being depressurized will cause Brute damage. Worsening Brute damage may cause broken bones, damaged organs and bleeding.

Sutures and bruise packs are useful for treating minor damages.
The Tend Wounds (Brute) surgery is the bread and butter of most doctors aboard a ship, healing wounds with time as the cost.
Chemicals like bicaridine can treat brute damage.
Broken bones can be fixed with surgery.

Burn Damage

The second most common source of damage, reflected in orange, visible and specific to each limb. High or low temperatures, getting shocked or shot with lasers will cause Burn damage. Burn damage that goes over 200 will cause the patient to be Husked, which prevents them from being revived.

Regenerative mesh can heal minor burns.
Once more, the Tend Wounds (Burn) surgery is the bread and butter of doctoring aboard ships.
Husks can be unhusked with 5u of Rezadone or 100u of Synthflesh when below 50 burn damage.

Toxin Damage

The third most seen source of damage, reflected in green. Breathing in bad air, radiation, eating bad food and getting injected with harmful chemicals or the wrong blood type cause Toxin damage. Toxin damage is unique in that it is hard to treat once the patient is dead, as it is healed mostly with chemicals, and these do not work on dead patients.

Toxin damage is mostly healed with chemicals, such as charcoal.
Vomiting slightly heals some toxin damage. If the patient is Dead, you can apply the Stomach Pump surgery to force them to vomit, also regurgitating some chemicals on the way out.

Organ Damage

Though not one of the big four, it's still important to keep track of organ damage. It is most often encountered on dead patients as their body decomposes. Brain damage causes traumas, heart and lung damage causes suffocation, eye and ear damage cause blindness and deafness respectively, and liver, appendix and stomach damage all cause toxin damage, with the stomach also worsening or outright preventing you from digesting food.

The brain, the lungs, the liver, the eyes, and the stomach can all be fixed to an usable state with specific surgery, which you need to research. You can also just yank out the appendix and eat it or something. It's in the groin.
Eyes and ears can be repaired with certain chemicals as well.
You can perform transplants with the Organ Manipulation surgery. You're going to need organs from either research or a willing donor (that drugged up guy you found on a beach planet, for example).

Standard Operating Procedure

Some miner just came back from their hunting trip and they are screaming at you to heal them. What do you do?

First, use your health analyzer. This item allows you to determine how much damaged someone has. Every medkit comes with one. Then, determine that wounds they have and treat them in order (Oxy, Tox, Burn, Brute) - in most cases, if they're just slightly (slightly being defined as ~30-50 damage) hurt, you can use a few sutures and/or regenerative mesh. If they're badly hurt, it's better to use chemistry or surgery for their wounds. If they have broken bones, you need to operate on them to fix them.

Ghetto Medical: Scalpel, Screwdriver, Energy Sword

Okay, say you're a Pill-class prisoner. Some poor sod just walked outside, and got their ass handed to them on a silver platter by a terrible smelling pirate with a hunting rifle fourty times older than themselves. Your friend's guts are spilling out of their body, you have absolutely no medical equipment or experience, and you searched up this guide expecting an actually well written one. What the hell do you do? You do ghetto medical!

First, jab them with an EpiPen. There will (almost) always be one in your internals box on your backpack. It contains three units of Formaldehyde, which preserve the organs inside a patient's body. You should always do this on a dead patient (unless it's a Vox, which are allergic to Epinephrine and suffer Toxin Damage). Then you can look at them and see what they have. It's most likely going to say severe bruising or burns, which are Brute Damage and Burn Damage respectively. Afterwards, look for a toolbox. Inside a toolbox is almost everything you need for a surgery bag substitute - you'll be lacking the saw and the scalpel, however. You can start surgeries with a screwdriver, no table required (but would be very much appreciated)! You'll need the patient to be on the floor for this.

In order to do a Tend Wounds surgery, you need something to start the surgery (a screwdriver or a surgical tool), something sharp (a glass shard, a knife...) to cut into the body, something to start Healing Wounds (screwdriver), and something to finish up the surgery (a welder, a candle, a lighter, a match).

Once you're done with that, you're going to need to proceed with Revival Surgery. This is done by cutting open the head, and shocking it with a stun baton or a defibrillator, which you most likely won't have, so you'll have to make-do with a stunprod. If you don't know where to get a cell, you can rip a charged one off an APC. You also need to saw through bone, which can be done with a hatchet (or anything sharp, actually, but the chance is incredibly low and basically zero with no surgery table).

Good Things to Know

Check out the Guide to Surgery and the Guide to Chemistry. Useful stuff!
Vox are allergic to Epinephrine, and will react in their bloodstream to cause Histamine, which is a toxin.
Jellypeople treat toxins damage inversely. That is, things that would be poisonous to a human heal toxins on jellypeople and vice-versa.
You should keep a bottle of Formaldehyde around for dead patients. You only need one unit to preserve the corpses.