Health Conditions
A health condition is a negative state affecting your Seedling's body and abilities. Injuries (burns, cuts, strains) make a Seedling Injured; illnesses (stomach trouble, coughs, headaches, eye problems) make them Sick. Each condition affects a specific body part, reduces Stats while active, and usually brings a negative thought. Injuries heal on their own and never worsen, but illnesses can worsen if left untreated, and the most serious can become life-threatening. See conditions in the Status Effect panel and in Focus Mode, where the Body System view shows each condition's severity, cause, affected Stats, duration, whether it can worsen or kill, and how to treat it.
Where conditions come from: accidents at work (failing demanding activities: furnaces and chemistry stations cause burns, workbenches and sharp tools cause cuts, heavy work causes strains, mining irritates eyes and chest; the lower the skill, the more likely they are to fail and the worse the result, though routine work carries well under a 1% injury risk); contaminated food and drink (unpurified Murky Water can cause Jaundice; raw mushrooms or raw algae can cause Indigestion, so purify water and cook food); and declining wellbeing (a run-down Seedling can develop headaches or palpitations. Keeping needs satisfied is the best prevention).
Severity: every condition is Minor, Moderate, or Severe. Minor conditions affect Stats slightly and can usually be self-treated. Moderate conditions are more noticeable; many can be self-treated but some need a doctor. Severe conditions are critical, can be life-threatening, and almost always need a skilled doctor and a specific remedy.
Worsening and healing: this applies to illnesses only, injuries always heal by themselves. An untreated illness can progress from Minor to Moderate to Severe, and a Severe illness can be fatal. Worsening happens as the illness's timer runs out or if the Seedling is exposed to its cause again. Treat early. Some remedies remove a condition outright; most greatly improve the odds it heals instead of worsening. After recovering, a Seedling gains temporary immunity to that condition.
Treatment
Self-treatment: for most minor and moderate conditions, the Seedling treats themselves with the right remedy within reach; they head to a suitable spot and apply it on their own. You can kick off a self treat straight from the Seedling's context menu.
Doctor treatment: more serious conditions must be treated by another Seedling acting as a doctor, performing a treatment activity on the patient with the required remedy.
Not every treatment is a single step: some remedies clear a condition in one application, others are an ongoing course, and the most serious allow only one decisive procedure. A condition's detail panel in Focus Mode always tells you which remedy it needs and whether self-treatment is possible.
Medical Skills
Medicine is the foundation of the medical skill tree. First Aid (available once Medicine is started) lets a Seedling treat their own minor and moderate conditions. Pharmacy is the craft of making remedies at the Medical Fabricator. Every society that wants to stay healthy needs at least one Seedling working on this. At First Aid level 20, specialist doctor skills open up, each covering part of the body: Wound Care, Burn Care, Cardiology, Gastroenterology, Nephrology, Neurology, Ophthalmology, Dentistry, Physiotherapy, Traumatology, Infectiology, and Fracture Care. Higher skill raises treatment success and speed. A Seedling only attempts a treatment on their own if they feel confident (confidence grows with skill level); if their skill is low, you can use Direct Control to have them attempt it anyway. One related skill sits outside the tree: Water Treatment lets a Seedling operate water pumps and filtration units to produce clean water, a good way to prevent waterborne illness before it starts.
Remedies
Remedies are consumable items that treat specific conditions and severities. Self-applied: Painkillers, Antibiotics, Antacids, Bandages, Cooling Gel, Muscle Relaxant, Cough Syrup, Eye Drops. Doctor-applied: Splints, Surgical Repair Kits, Advanced Burn Treatment Kits, Anesthetic, IV Catheters, Defibrillators, Oxygen Masks. Remedies are crafted from schematics (primarily at the Medical Fabricator by a Seedling with Pharmacy), or bought from the Marketplace or traded. They have a shelf life and eventually decay, so keep a fresh supply stocked in nearby containers. Basic remedies like bandaids and antiseptics can be crafted early on, and each remedy's Catalog entry lists every condition it can treat.