Category
Levels of specialisation and how you reach them — a structure designed so that most problems are dealt with close to home by generalists, and specialist capacity is reserved for what needs it.
By assessing whether a treatment represents an acceptable use of limited resources — combining how well it works with what it costs, since a health service with a fixed budget funding one thing
Because the eye's optics and its length do not match — light is brought to a focus in front of the retina, behind it, or unevenly, and a lens corrects the mismatch. How focusing works. Light is bent
Sepsis is the body's own response to an infection going wrong and damaging its own tissues and organs. It is not a specific infection — it is what can happen with almost any infection, anywhere in
They are fundamentally different kinds of thing, not variations on a theme — which is why treatments for one do nothing for another. Bacteria. Single-celled living organisms with their own
It means a licensed medicine is being used outside the terms of its licence — a different condition, a different age group, a different dose or a different route than the one it was formally approved
Because screening tests people who feel well, and that changes the arithmetic completely — a test that is useful for someone with symptoms can do net harm when applied to a whole healthy population.
Each phase answers a different question, and the questions get progressively harder — which is why most drugs that enter testing never reach patients. Preclinical. Laboratory and animal studies
Remarkably well, and we do not fully know why — which is one of the more striking gaps in modern medicine given that it is administered millions of times a year with an excellent safety record. What
Because pain is produced by the brain, not delivered by the body — and the brain is weighing a great deal more than tissue damage when it decides how much to produce. The old model was wrong. For
Because emergency departments run on triage — sorting by clinical urgency rather than arrival order — and the alternative would mean people with life-threatening conditions waiting behind minor
They describe three different things, and the distinctions are used precisely in medicine even though everyday speech treats them as interchangeable. Symptom. Something the patient experiences and
The incubation period is the time between being infected and developing symptoms. It varies by disease, and understanding it explains a great deal about how infections spread. What is happening
Because the immune system is designed to identify and destroy anything not recognised as self, and a donated organ is genetically foreign tissue. How the immune system tells self from non-self.
The leading explanation is sensory conflict — your balance system and your eyes reporting different things about whether you are moving. How balance normally works. The vestibular system in the inner
Depends entirely which test, and "a blood test" covers dozens of different panels measuring different things. The common ones fall into a few groups. Full blood count (FBC). Counts and characterises
Because of a specific and unusual physiological response called the vasovagal reflex, and the pattern it follows is the opposite of what most people assume. The mechanism. Most frightening situations
Because the infection clearing and the airways recovering are separate processes, and the second takes considerably longer. What a cough is. A protective reflex clearing the airways, triggered by
The microbiome is the community of microorganisms living in and on your body — bacteria overwhelmingly, plus fungi, viruses and archaea. Most live in the large intestine. The numbers. An
Because the stress response is a whole-body physiological state evolved for physical emergencies, and running it continuously produces real effects in tissues that have nothing to do with
Because our jaws changed faster than our teeth did, and the mismatch is recent in evolutionary terms. What they are. The third molars, usually erupting between 17 and 25 — the origin of the name,
A vaccine gives your immune system a rehearsal — exposure to something resembling a pathogen, so that memory is built without the illness. The two-stage immune response. Meeting a new pathogen, the
Because a medicine carries up to three distinct names serving different purposes, and confusing them is a genuine source of medication errors. The chemical name describes the molecular structure
Herd immunity (or population immunity) is the indirect protection that arises when a sufficiently large proportion of a population is immune to an infection, so transmission chains break down and