Health & Medicine (Advanced) — B2 Essential Words

surgery /ˈsɜːrdʒəri/ noun B2 Health

Meaning: Medical treatment in which a doctor cuts into the body to repair or remove something damaged or diseased.

Example: He needs knee surgery.

Another example: The surgery lasted three hours.

Collocations: heart surgery · surgery on · undergo surgery

Synonyms: operation, procedure

Word family: surgeries (n pl) · surgeon (n) · surgical (adj)

⚠ Common mistake: The doctor is a SURGEON; the event is surgery (US) or an operation. 'Undergo surgery' is the formal patient phrase.

🗣 In spoken American English: From appendix to heart, the word families fear and trust most.

Register: Formal — medical essential.

infection /ɪnˈfekʃən/ noun B2 Health

Meaning: A disease or illness caused by harmful bacteria or viruses entering the body; the process of being infected.

Example: The cut shows signs of infection.

Another example: Ear infections are common in children.

Collocations: infection in · risk of infection · serious infection

Synonyms: contamination, illness, disease (wider)

Word family: infections (n pl) · infect (v) · infectious (adj)

⚠ Common mistake: Infectious diseases spread between people; an infection stays (mostly) in one body. Antibiotics fight bacterial ones, not viruses.

🗣 In spoken American English: Hand-washing's whole career is preventing this one word.

Register: Formal — medical essential.

prescription /prɪˈskrɪpʃən/ noun B2 Health

Meaning: An official note from a doctor telling a pharmacist which medicine a patient should receive; the medicine itself.

Example: The doctor wrote a prescription for antibiotics.

Another example: Pick up your prescription at the pharmacy.

Collocations: write a prescription · prescription for · fill a prescription

Synonyms: order (doctor's), medication

Word family: prescriptions (n pl) · prescribe (v)

⚠ Common mistake: You FILL a prescription at the pharmacy. Some medicines need one ('prescription drugs'); others are 'over the counter'.

🗣 In spoken American English: The pharmacist's counter runs on them all day.

Register: Formal — pharmacy essential.

dose /dəʊs/ noun B2 Health

Meaning: The measured amount of medicine taken at one time.

Example: Take one dose every eight hours.

Another example: The dose for children is smaller.

Collocations: a dose of · daily dose · dose instructions

Synonyms: amount, measure, portion

Word family: doses (n pl) · dosage (n — the regimen) · overdose (n/v)

⚠ Common mistake: A dose is one taking; dosage is the whole pattern (amount + timing). An overdose is a dangerous excess.

🗣 In spoken American English: Labels guard it strictly: 'Do not exceed the stated dose.'

Register: Formal — medicine essential.

diagnosis /ˌdaɪəɡˈnəʊsɪs/ noun B2 Health

Meaning: A doctor's judgment about what illness a patient has, after examining them and their tests.

Example: The diagnosis was good news: nothing serious.

Another example: Early diagnosis saves lives.

Collocations: make a diagnosis · diagnosis of · early diagnosis

Synonyms: finding, conclusion, assessment

Word family: diagnoses (n pl) · diagnose (v) · diagnostic (adj)

⚠ Common mistake: Diagnosis (what it is) pairs with prognosis (what will happen). Doctors MAKE diagnoses after tests, not guesses.

🗣 In spoken American English: The moment every waiting room holds its breath for.

Register: Formal — medical core.

chronic /ˈkrɒnɪk/ adjective B2 Health

Meaning: Continuing for a long time or returning again and again (especially illnesses and problems).

Example: He suffers from chronic back pain.

Another example: Chronic stress damages sleep.

Collocations: chronic pain · chronic disease · chronic problem

Synonyms: long-term, persistent, ongoing

Antonyms: acute (sudden, short), temporary

Word family: chronically (adv)

⚠ Common mistake: Chronic (long/slow) vs acute (sudden/short) is medicine's great time contrast. Chronic is NOT about severity.

🗣 In spoken American English: Doctors manage it for years; patients live it daily.

Register: Formal — medical essential.

virus /ˈvaɪrəs/ noun B2 Health

Meaning: A tiny living agent that enters the body and causes diseases like flu and colds; also a harmful computer program.

Example: The flu virus spreads in winter.

Another example: A virus infected his laptop.

Collocations: a stomach virus · virus infection · computer virus

Synonyms: germ (general), pathogen, bug (informal)

Word family: viruses (n pl) · viral (adj)

⚠ Common mistake: Antibiotics do NOT kill viruses — the most repeated sentence in medicine. 'Going viral' stole the word for internet fame.

🗣 In spoken American English: One word rules winter clinics and computer shops alike.

Register: Neutral to formal — health and tech.

bacteria /bækˈtɪəriə/ noun B2 Health

Meaning: Very small living things, some of which cause disease and others that help the body (in the gut, in soil).

Example: Some bacteria cause food poisoning.

Another example: Good bacteria help digestion.

Collocations: harmful bacteria · bacteria in · kill bacteria

Synonyms: germs, microbes, organisms

Word family: bacterium (n — singular, rare) · bacterial (adj)

⚠ Common mistake: Bacteria is already PLURAL (one is a bacterium, rarely said). Not all bacteria are enemies — your gut hosts trillions of helpers.

🗣 In spoken American English: Yogurt ads and hospital posters fight over the same word.

Register: Formal — biology essential.

immune /ɪˈmjuːn/ adjective B2 Health

Meaning: Protected against a disease, so it cannot harm you; related to the body's defense system.

Example: After the vaccine, you're immune to the disease.

Another example: The immune system fights infections.

Collocations: immune system · immune to · immune response

Synonyms: protected, resistant

Antonyms: vulnerable, susceptible

Word family: immunity (n) · immunize (v)

⚠ Common mistake: Immune TO a disease. The immune SYSTEM is the body-wide defense — sleep, food, and vaccines all train it.

🗣 In spoken American English: Wellness culture's favorite system to 'boost'.

Register: Formal — health essential.

psychology /saɪˈkɒlədʒi/ noun B2 Health

Meaning: The scientific study of the mind and how it influences behavior.

Example: She studies psychology at the university.

Another example: Child psychology helps teachers understand learning.

Collocations: study psychology · psychology of · child psychology

Synonyms: mind science, behavioral science

Word family: psychologist (n) · psychological (adj)

⚠ Common mistake: The P is silent: sy-KOL-uh-jee. A psychologist studies minds and helps people; a psychiatrist is a medical doctor who prescribes — keep them apart.

🗣 In spoken American English: Every marketing team hires it now: the psychology of clicks.

Register: Formal — academic essential.