Full forms: science and medicine

44 full forms, each with a line on what it means.

Science uses short forms for long chemical names, for instruments and for units; hospitals use them for departments, tests and conditions. This page explains those that appear in school science and on medical papers: the molecules of life, terms of electricity and light, common materials, and the words on a hospital signboard or a laboratory report. It explains what a term means. It is not medical advice, and it does not tell you what a test result means for you; ask your doctor that. Three of the entries, LASER, RADAR and SONAR, began as initials and are now ordinary words usually written in small letters.

Explained in full: DNA

• DNA

  Deoxyribonucleic Acid

  The molecule in living cells that carries the genetic instructions passed from parents to offspring.

  DNA explained Copy

• RNA

  Ribonucleic Acid

  A molecule that carries genetic messages within the cell and helps make proteins.

  Copy

• ATP

  Adenosine Triphosphate

  The molecule that carries energy for use inside living cells.

  Copy

• pH

  Potential of Hydrogen

  A scale from 0 to 14 that shows how acidic or basic a solution is; 7 is neutral.

  Copy

• LASER

  Light Amplification by Stimulated Emission of Radiation

  A device that gives a narrow, intense beam of light of a single colour.

  Copy

• RADAR

  Radio Detection and Ranging

  A system that finds distant objects by bouncing radio waves off them.

  Copy

• SONAR

  Sound Navigation and Ranging

  A system that finds objects under water using sound waves.

  Copy

• AC

  Alternating Current

  Electric current that reverses direction many times a second, as in mains supply. AC is also short for air conditioner.

  Copy

• DC

  Direct Current

  Electric current that flows in one direction, as from a battery.

  Copy

• EMF

  Electromotive Force

  The voltage produced by a cell or generator.

  Copy

• SI

  Système International

  As in SI units: the international system of units of measurement, from its French name. In the police, SI means sub-inspector.

  Copy

• STP

  Standard Temperature and Pressure

  Agreed reference conditions for comparing gases.

  Copy

• UV

  Ultraviolet

  Light with a wavelength shorter than violet, invisible to the eye; it causes sunburn.

  Copy

• IR

  Infrared

  Light with a wavelength longer than red, felt as heat; remote controls use it.

  Copy

• CFC

  Chlorofluorocarbon

  A group of gases once used in refrigerators and sprays, which damage the ozone layer.

  Copy

• PVC

  Polyvinyl Chloride

  A common plastic used for pipes, wire insulation and flooring.

  Copy

• TNT

  Trinitrotoluene

  A well-known explosive.

  Copy

• BMI

  Body Mass Index

  A number worked out from weight and height, used as a rough guide to healthy weight.

  Copy

• BP

  Blood Pressure

  The pressure of blood in the arteries, given as two numbers such as 120/80.

  Copy

• ECG

  Electrocardiogram

  A recording of the electrical activity of the heart.

  Copy

• MRI

  Magnetic Resonance Imaging

  A scan that uses strong magnets and radio waves to picture the inside of the body.

  Copy

• CT

  Computed Tomography

  As in CT scan: X-ray pictures taken from many angles and combined by a computer.

  Copy

• ICU

  Intensive Care Unit

  The hospital ward for patients who need constant monitoring and support.

  Copy

• OPD

  Outpatient Department

  The part of a hospital where patients are seen without being admitted.

  Copy

• OT

  Operation Theatre

  The room where surgery is done. At work, OT means overtime.

  Copy

• ORS

  Oral Rehydration Solution

  A mix of salts and sugar in water, given to replace fluids lost in diarrhoea.

  Copy

• HIV

  Human Immunodeficiency Virus

  The virus that attacks the immune system and can lead to AIDS.

  Copy

• AIDS

  Acquired Immunodeficiency Syndrome

  The advanced stage of infection with HIV.

  Copy

• TB

  Tuberculosis

  An infectious disease, usually of the lungs, caused by bacteria.

  Copy

• RBC

  Red Blood Cell

  The blood cell that carries oxygen.

  Copy

• WBC

  White Blood Cell

  The blood cell that fights infection.

  Copy

• CBC

  Complete Blood Count

  A common blood test that counts the different blood cells.

  Copy

• IVF

  In Vitro Fertilisation

  A treatment in which an egg is fertilised outside the body.

  Copy

• ENT

  Ear, Nose and Throat

  The medical speciality, and its specialist, for these parts.

  Copy

• PCOD

  Polycystic Ovarian Disease

  A common hormonal condition in women, also called PCOS.

  Copy

• COVID

  Coronavirus Disease

  As in COVID-19, the disease caused by the coronavirus first reported in 2019.

  Copy

• PPE

  Personal Protective Equipment

  Protective clothing and gear such as masks, gloves and gowns.

  Copy

• BCG

  Bacillus Calmette-Guérin

  The vaccine against tuberculosis, named after the two scientists who developed it.

  Copy

• ASHA

  Accredited Social Health Activist

  A trained woman health worker in an Indian village.

  Copy

• AYUSH

  Ayurveda, Yoga and Naturopathy, Unani, Siddha and Homoeopathy

  The systems of medicine covered by the Ministry of AYUSH.

  Copy

• RO

  Reverse Osmosis

  A method of purifying water by forcing it through a fine membrane.

  Copy

• TDS

  Total Dissolved Solids

  A measure of the minerals and salts dissolved in water. In tax, TDS is tax deducted at source.

  Copy

• EV

  Electric Vehicle

  A vehicle driven by an electric motor and battery.

  Copy

• GMO

  Genetically Modified Organism

  A plant or animal whose genes have been changed in a laboratory.

  Copy

How to read an entry

The letters in bold are the short form as it is normally written. Under it is the full form, and then a line of meaning in plain words. Where the same letters mean something else in another field, the entry mentions it. "Copy" puts the short form, the full form and the meaning on your clipboard, ready to paste into notes or a message.

Check what matters. These pages explain names and terms in general. Rules, dates, fees and limits change: take them from the official body. Read on 12 November 2026.

Other subjects

School, boards and exams Degrees and courses Computers and internet Mobile and telecom Banking, tax and money Government, law and services World bodies, countries and sport Transport and travel Office and business Chat, letters and everyday