Medical language, human language

We don’t shorten a term until it loses its meaning; we explain it until it makes sense. Each term answers four questions: what does it mean, simply? What does it not mean? Why do doctors use it? And what can you ask?

The meaning of a word is not the meaning of your case. The same term can be minor for one person and important for another, depending on symptoms, examination and context.

Have a report? Paste it and we’ll pick out the terms

EEG (electroencephalogram)

What does it mean, simply?: A recording of the brain’s electrical activity through small sensors placed on the scalp. It doesn’t hurt and it puts no electricity into the brain; the machine only listens.
What does it not mean?: A normal EEG does not rule out epilepsy, because the recording is short and may catch nothing between seizures. And an EEG with “changes” does not always mean epilepsy.
Why do doctors use it?: It helps work out the type of seizures, and in intensive care it is used to look for seizures that don’t show on the body in a patient who isn’t awake.
A question you can ask: What question was the EEG meant to answer, and did it answer it?

MRI

What does it mean, simply?: A detailed picture of the brain made with a magnetic field, without X-rays. It usually takes 20 to 50 minutes; the machine is loud but harmless.
What does it not mean?: Many causes of headache and seizures never show on MRI. A normal scan does not mean your symptoms aren’t real.
Why do doctors use it?: It sees small strokes, white-matter disease and structural causes of epilepsy better than CT.
A question you can ask: What exactly are you looking for, and will I need contrast dye?

CT scan

What does it mean, simply?: A fast X-ray scan that takes minutes. It is usually the first test in the emergency department.
What does it not mean?: A normal CT in the first hours does not rule out a stroke; many strokes don’t show on CT early on.
Why do doctors use it?: It is excellent at showing bleeding quickly, which the doctor needs to know before deciding on stroke treatment.
A question you can ask: Is a CT enough in my case, or will I need an MRI later?

Lumbar puncture

What does it mean, simply?: Taking a small amount of the fluid around the brain and spinal cord with a fine needle in the lower back.
What does it not mean?: The needle goes in below the level where the spinal cord ends, so it does not touch it. A headache afterwards can happen; it usually settles with rest and sometimes needs simple treatment.
Why do doctors use it?: It can show infection, bleeding that a scan may miss, some immune diseases, and the pressure of the fluid.
A question you can ask: What will you look for in the fluid, and when will the results be back?

Lesion

What does it mean, simply?: A very general word for an area that looks different from the tissue around it.
What does it not mean?: It does not mean a tumour, cancer, or anything serious by itself. It can be an old scar, inflammation, a small stroke, or something of no importance.
Why do doctors use it?: Radiologists use it to describe what they see before the cause is known. It is a description, not a diagnosis.
A question you can ask: What are the most likely explanations for this lesion, and does it need follow-up or another test?

White spots / hyperintensities

What does it mean, simply?: Areas that look brighter than their surroundings on some MRI sequences. “High signal” describes the brightness in the picture.
What does it not mean?: Small white spots are very common and increase with age, blood pressure, diabetes and migraine. On their own they do not mean multiple sclerosis or dementia.
Why do doctors use it?: The doctor weighs their shape, location and number against your age and symptoms to decide whether they matter.
A question you can ask: Are these spots expected for my age and risk factors, or does their pattern need follow-up?

White matter

What does it mean, simply?: The brain’s “wiring”: the fibres that connect its regions, lying deep beneath the surface.
What does it not mean?: When a report mentions white matter, it is naming a place, not a disease.
Why do doctors use it?: Many changes, such as white spots, small-vessel disease and multiple sclerosis, are described by where they sit in it.
A question you can ask: Do the white-matter changes explain my symptoms?

Small vessel disease

What does it mean, simply?: Changes in the tiny arteries deep in the brain, usually seen as white spots in the white matter.
What does it not mean?: It is not a major stroke, and it doesn’t necessarily cause symptoms now.
Why do doctors use it?: It is linked to blood pressure, diabetes, smoking and age; controlling these is what protects the brain in future.
A question you can ask: What can I do about blood pressure, sugar and cholesterol to protect these vessels?

Atrophy

What does it mean, simply?: The brain looks smaller than expected, with wider spaces around it.
What does it not mean?: Some atrophy is normal with ageing and does not by itself mean dementia. The key question is whether it fits your age.
Why do doctors use it?: The pattern and location of atrophy can help in understanding some memory disorders, but cannot diagnose them alone.
A question you can ask: Is the atrophy in keeping with my age, or more than expected?

Contrast enhancement

What does it mean, simply?: An area that took up the dye and looks brighter, which happens when the barrier that protects the brain from parts of the blood is disturbed.
What does it not mean?: It does not necessarily mean a tumour; it happens with inflammation, infection, some strokes in their first weeks, and more.
Why do doctors use it?: It helps judge how active a problem is and how old it is, for example in multiple sclerosis.
A question you can ask: What does enhancement mean in my case, and do I need a follow-up scan?

Demyelination and plaques

What does it mean, simply?: Damage to the insulating sheath around nerve fibres, which slows the signals they carry. “Plaques” are the areas of damage.
What does it not mean?: “May be consistent with demyelination” is not the same as a diagnosis of multiple sclerosis; diagnosis has criteria that combine scans, symptoms and examination.
Why do doctors use it?: The shape and location of the spots, such as around the ventricles or in the spinal cord, matter in assessing MS and its look-alikes.
A question you can ask: Do I meet the criteria for a diagnosis, or is this a finding to watch?

Nonspecific

What does it mean, simply?: What the doctor saw does not point to one particular cause; it has more than one possible explanation.
What does it not mean?: It does not mean “serious and hidden”, and it does not quite mean “nothing”. It means the phrase alone can’t settle it.
Why do doctors use it?: It is an honest way of saying the finding has to be read together with the patient’s story and examination.
A question you can ask: Given my symptoms and examination, how do you read this finding?

Incidental finding

What does it mean, simply?: Something found by chance while looking for something else.
What does it not mean?: It is usually unrelated to the symptoms that led to the scan, and much of it needs no treatment.
Why do doctors use it?: It is reported because radiologists describe everything they see; your doctor then decides whether it needs follow-up.
A question you can ask: Does this finding need follow-up, or can it safely be left?

Unremarkable

What does it mean, simply?: In report language it means “normal”: nothing worth mentioning was seen.
What does it not mean?: It does not mean nobody looked carefully. And a normal test doesn’t make symptoms unreal; many neurological conditions don’t show on scans.
Why do doctors use it?: A traditional, compact phrase in reports.
A question you can ask: If the scans are normal, what is the most likely explanation for my symptoms?

Acute / chronic

What does it mean, simply?: “Acute” means recent or sudden; “chronic” means old or long-standing.
What does it not mean?: “Acute” does not mean “severe”, and “chronic” does not mean “untreatable”.
Why do doctors use it?: The age of a change matters: a recent one may need treatment now, an old one is read in the light of the history.
A question you can ask: Is what the report describes recent or old, and how can you tell?

Mass effect and midline shift

What does it mean, simply?: Something inside the skull, such as bleeding, swelling or a tumour, takes up space and pushes on what is around it. “Midline shift” means the brain has been pushed to one side.
What does it not mean?: It describes the effect, not the cause. It is measured in millimetres, and its importance varies a lot.
Why do doctors use it?: It is one of the first things doctors look at in acute illness, because it may call for urgent treatment or surgery.
A question you can ask: Is the mass effect getting worse or stable, and what is the plan to relieve it?

Stroke

What does it mean, simply?: Sudden damage to part of the brain because an artery is blocked or bursts.
What does it not mean?: Strokes are not all alike; the type, size and location change treatment and recovery a great deal.
Why do doctors use it?: The word covers several conditions, which is why doctors ask many questions to pin down the type and cause. In ischaemic stroke, time is part of the treatment: some people can have the clot dissolved or removed up to 24 hours after onset, depending on the scans.
A question you can ask: What type of stroke was it, what caused it, and what lowers the chance of another?

Ischaemia

What does it mean, simply?: Less blood reaching part of the brain than it needs, so it gets less oxygen.
What does it not mean?: It does not always mean permanent damage has happened; ischaemia can be temporary and can sometimes be treated if caught early.
Why do doctors use it?: It is the mechanism behind most strokes. “Ischaemic stroke” means a stroke caused by a blockage, not by bleeding.
A question you can ask: Is the ischaemia recent or old, and what is the most likely cause?

Infarct

What does it mean, simply?: An area where cells have died because the blood supply stopped. It is how an ischaemic stroke looks on a scan.
What does it not mean?: An “old infarct” may have happened years ago without anyone noticing, and does not mean a stroke now.
Why do doctors use it?: The size and location of the infarct shape the expected symptoms and the chances of recovery.
A question you can ask: Is the infarct new or old, and does it change my preventive medicines?

Restricted diffusion (DWI)

What does it mean, simply?: A sign on a special MRI sequence that usually appears when cells have been injured recently, often in the first days.
What does it not mean?: It is typical of a recent stroke, but can also follow long seizures, and appear with some infections and tumours.
Why do doctors use it?: It helps tell whether a problem is recent or old.
A question you can ask: Does restricted diffusion here mean a recent stroke, or is there another explanation?

TIA (transient ischaemic attack)

What does it mean, simply?: Stroke-like symptoms, such as weakness, speech trouble or loss of vision, that go away on their own within minutes or hours.
What does it not mean?: “The symptoms went away” does not mean “the problem is over”. It is a warning; the risk of a full stroke is higher in the following days.
Why do doctors use it?: It needs urgent assessment to find the cause and start prevention.
A question you can ask: What caused this, and what should I start now to lower the risk of a stroke?

Haemorrhage (bleeding)

What does it mean, simply?: Blood outside the blood vessels, inside or around the brain. There are many types, named by location.
What does it not mean?: The word alone doesn’t tell you how serious it is; a tiny old bleed is very different from a large new one. Microbleeds are common with age and small-vessel disease.
Why do doctors use it?: The type and location of the bleed decide the treatment: watching, blood pressure control, or surgery.
A question you can ask: What type of bleed is it, is it new, and does it affect blood thinners?

Oedema (swelling)

What does it mean, simply?: A build-up of fluid that makes brain tissue swell, around a stroke, bleed, tumour or inflammation.
What does it not mean?: Swelling is a reaction rather than a separate disease, and it often settles with time or treatment.
Why do doctors use it?: If it grows it can press on nearby tissue, which is why the team watches it closely, especially in intensive care.
A question you can ask: Is the swelling increasing or stable, and what is the plan for it?

Seizure

What does it mean, simply?: A brief burst of excessive, synchronised electrical activity in the brain. It can look like convulsions, staring, movements or a strange feeling, depending on the area involved.
What does it not mean?: One seizure does not mean epilepsy. And not every “fit” is an epileptic seizure; fainting and some non-epileptic attacks look similar.
Why do doctors use it?: Doctors use it to describe the event itself, before looking for its cause and type.
A question you can ask: Was this really an epileptic seizure, and what makes you think so?

Epilepsy

What does it mean, simply?: A lasting tendency of the brain to have repeated seizures. It is usually diagnosed after two unprovoked seizures, or after one when the chance of another is high.
What does it not mean?: It is not a psychiatric illness, it is not possession, and it does not mean lower intelligence. Most people with epilepsy have their seizures controlled with medicine.
Why do doctors use it?: The diagnosis affects important decisions: medicine, driving, work and pregnancy.
A question you can ask: What type of epilepsy do I have, and what does it mean for driving, work and pregnancy?

Epileptiform discharges

What does it mean, simply?: Wave shapes on the EEG that resemble those seen in people with epilepsy, such as “spikes” and “sharp waves”.
What does it not mean?: They are not a diagnosis of epilepsy on their own; a small number of people without epilepsy have them. The story matters more than the EEG.
Why do doctors use it?: After a first seizure they raise the chance of another, and they help identify the type and location of epilepsy.
A question you can ask: Does this result change the treatment decision, or is it supporting information?

Slowing on the EEG

What does it mean, simply?: Waves that are slower than usual, either in one area (focal) or across the whole brain (diffuse).
What does it not mean?: It doesn’t point to one disease. Diffuse slowing is common with drowsiness, sedating medicines, infection and salt imbalances.
Why do doctors use it?: It gives an idea of how much brain function is affected, and where, if it is focal.
A question you can ask: Is the slowing focal or diffuse, and what is the likely cause in my case?

Status epilepticus

What does it mean, simply?: A seizure that hasn’t stopped within five minutes, or seizures one after another without waking in between.
What does it not mean?: It does not necessarily mean the brain has been damaged, but it is an emergency that needs treatment at once.
Why do doctors use it?: The longer a seizure lasts the harder it is to stop, so it is treated quickly in set steps.
A question you can ask: What caused it, and what is our plan at home if a seizure happens again?

ICU (intensive care unit)

What does it mean, simply?: A unit where a specialised team watches patients who need constant monitoring or support for vital functions such as breathing and blood pressure.
What does it not mean?: Being admitted to intensive care does not mean the person is about to die. Many go there for close monitoring after surgery, a stroke or seizures.
Why do doctors use it?: It allows the team to act within minutes if anything changes.
A question you can ask: Why does the patient need intensive care right now, and what are we waiting for before they can leave it?

Sedation

What does it mean, simply?: Medicines that keep a patient asleep or calm, to tolerate the breathing tube, ease pain, or protect the brain in some situations.
What does it not mean?: Being asleep because of sedation says little on its own about the state of the brain. The team often lightens it, sometimes daily, to check how the patient responds.
Why do doctors use it?: The aim is the least sedation that keeps the patient comfortable and safe.
A question you can ask: Is the patient asleep because of the medicines or because of the illness, and when will you lighten the sedation?

Ventilator and breathing tube

What does it mean, simply?: A tube in the windpipe connected to a machine that helps with breathing or takes it over, when the patient can’t protect their airway or breathe enough.
What does it not mean?: It does not mean the lungs have stopped, nor that the patient won’t wake up. Many need it for a few days and then come off.
Why do doctors use it?: It protects the lungs from saliva and food, secures oxygen, and gives the body time to recover.
A question you can ask: What needs to improve before you try taking the patient off the ventilator?

Glasgow Coma Scale (GCS)

What does it mean, simply?: A score from 3 to 15 that measures the level of consciousness from eye opening, speech and movement. 15 means fully awake.
What does it not mean?: The number alone does not predict the future, and it is affected by sedation and by the breathing tube, which prevents speech.
Why do doctors use it?: A shared language for doctors and nurses to follow change hour by hour.
A question you can ask: How has the score changed since admission, and what is affecting it now?

Encephalopathy / delirium

What does it mean, simply?: A general disturbance of brain function, showing as confusion, drowsiness or changed behaviour. Delirium is a common form of it in hospital.
What does it not mean?: It describes a state, not a cause. The causes are many: infection, salts, liver, kidneys, medicines, low oxygen.
Why do doctors use it?: It prompts the team to look for the cause, and many causes can be treated.
A question you can ask: What is the most likely cause, and do you expect it to improve?

Brain death

What does it mean, simply?: The complete, permanent and irreversible loss of all brain function, including the brainstem that controls breathing. It is recognised as death medically and legally in Saudi Arabia, the UK and most countries.
What does it not mean?: It is not a deep coma or a “vegetative state”; a person in a coma is alive and their brain still partly works. A heartbeat continuing on a ventilator does not mean the brain is working.
Why do doctors use it?: It is diagnosed only with strict, defined tests by qualified doctors, after ruling out anything that can mimic it, such as sedating drugs or low body temperature.
A question you can ask: Which tests were done, who did them, and was everything that could affect the result ruled out?

Aura

What does it mean, simply?: Temporary neurological symptoms before or during a migraine headache, most often shimmering zigzag lines or a blind spot that spreads slowly over minutes.
What does it not mean?: A typical aura is not a stroke. But a sudden new symptom, especially weakness, or an aura lasting more than an hour, needs urgent assessment.
Why do doctors use it?: Aura changes some treatment decisions, including contraceptive pills that contain oestrogen.
A question you can ask: Is what I see a typical aura, and does it change any medicine I take?

Medication-overuse headache

What does it mean, simply?: A headache that becomes almost daily because painkillers for attacks are taken often and for a long time.
What does it not mean?: It is not addiction or weak willpower, and it doesn’t mean painkillers are banned. It means the number of days you take them has crossed a threshold.
Why do doctors use it?: Recognising it matters because the headache usually improves when painkiller use is reset with a plan from your doctor.
A question you can ask: Does the number of days I take painkillers put me at risk, and what is the alternative plan?

Medical sources

Fisher RS et al. · Epilepsia · 2014ILAE official report: a practical clinical definition of epilepsy. Epilepsia 55(4):475–482. doi.org/10.1111/epi.12550
Trinka E et al. · Epilepsia · 2015A definition and classification of status epilepticus: report of the ILAE Task Force. Epilepsia 56(10):1515–1523. doi.org/10.1111/epi.13121
Sacco RL et al. · Stroke · 2013An updated definition of stroke for the 21st century: a statement for healthcare professionals from the AHA/ASA. Stroke 44(7):2064–2089. doi.org/10.1161/STR.0b013e318296aeca
Prabhakaran S et al. · Stroke · 20262026 Guideline for the early management of patients with acute ischemic stroke (AHA/ASA). doi.org/10.1161/STR.0000000000000513
Wardlaw JM et al. · Lancet Neurology · 2013Neuroimaging standards for research into small vessel disease and its contribution to ageing and neurodegeneration (STRIVE). Lancet Neurol 12(8):822–838. doi.org/10.1016/S1474-4422(13)70124-8
Greer DM et al. · JAMA · 2020Determination of brain death/death by neurologic criteria: the World Brain Death Project. JAMA 324(11):1078–1097. doi.org/10.1001/jama.2020.11586
International Headache Society · Cephalalgia · 2018The International Classification of Headache Disorders, 3rd edition (ICHD-3). Cephalalgia 38(1):1–211. doi.org/10.1177/0333102417738202

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