Glossary of Terms

This glossary of terms is meant to help everyone understand medical words. It is a place to quickly find information on medical words.

To find a word or term begin by clicking on a letter in the A-Z list. Then you can browse down the list to find the word you want. You can also type your medical word in the search box in the upper right corner and then click on the little magnifying glass.

This glossary is for information only. It should never be used instead of advice from a healthcare provider.

If you have questions or comments about the Glossary of Terms please let us know.

If there is a word you couldn't find or you have a suggestion, please send an email to @email

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echocardiogram or ECHO

a test that uses ultrasound to see how blood moves through your heart

see heart tests


skin rash



swelling of your body tissues (usually your ankles or lungs) due to sodium and water build up


make, result


works well, good, strong

efficacy rate

how well something works

eHealth Ontario

an electronic (computer) health record of your health history. It gives your healthcare team, including your family doctor, nurses, emergency department staff and specialists real-time access to your medical information.

to learn more go to

ejection fraction (EF)

is a measurement that tells how well your heart is working. This number shows how much blood your heart is pumping out each time it beats

is the percentage of blood pumped out of the ventricle (lower chamber of the heart) each time it contracts

electrocardiogram (ECG)

heart test

a quick test used record and document the hearts electrical activity (see heart tests)

electroencephalogram (EEG)

a test that measures brain waves (or the electrical activity of your brain)

electrolytes ("lytes")

blood salts

blood test that looks at the balance of sodium, potassium and chloride in your blood

electronic health record (EHR), electronic medical record (EMR)

a computer record of your health and the care you have received


lift, raise, raise higher


 throw out, get rid of, do away with


gaunt, thin, wasted, starving


blood clot


when a blood vessel is blocked by something, such as a blood clot (embolus)

therapeutic embolization is a nonsurgical, minimally invasive procedure performed by interventional radiologist. It involves the selective blockage of blood vessels by purposely introducing something to block the vessel.


anything that travels through the blood vessels until it reaches a vessel that is too small to let it pass. When this happens, the blood flow is stopped. An embolus is often a small piece of a blood clot that breaks off.


unborn baby (up to 12 weeks)

emergency cart/rainbow cart

rolling carts that contains supplies and medications needed to treat a child during a crisis.


a lung disease

a disease in which the lungs become stretched or enlarged (bigger) and breathing gets harder



swollen brain


a disease that damages the brain

end-of-life care

physical, emotional and spiritual care given at the end of your life. Also called comfort care.

end-stage renal disease (ESRD)

when your kidneys have stopped working, you can't survive without dialysis or a transplant

stage 5 in chronic kidney disease when treatment such as dialysis or transplantation is necessary. "End stage" refers to the end of kidney function. Also called end-stage renal failure or end-stage kidney failure.


hormone system


a doctor who has special training in looking after people with problems in their endocrine glands


the study of your endocrine system



a condition where the tissue that usually grows inside your uterus grows outside of your uterus


the lining inside of your uterus


a test that allows a doctor to look inside of your body using a small camera

endotracheal (ET) tube

 flexible plastic tube placed into your airway, through your nose or mouth to help you breathe.


add to, improve


make sure

enteral feeding (enteral nutrition, tube feeding)

when special, liquid food is given to you through a tube in your nose or mouth, or a tube that goes directly into your stomach or small intestine


all the things around you


cells that help protect you from germs


when you have a high number of eosinophils, it tells you that you could have an infection


needle filled with medication for allergic reactions

This medication is used in emergencies to treat very serious allergic reactions to insect stings/bites, foods or drugs.

epicardial Wires

there are two types:

  • temporary epicardial wires (sutures) sewn to the surface of the heart after cardiac surgery that allows for temporary pacemaking of the heart if needed
  • permanent epicardial wires (sutures) which are inserted into the heart when a pacemaker or defibrillator is inserted

disease that most people get, widespread sickness


study of disease




painkilling medication is given to you through a very small tube in your back. This might be done when you are in labour or after surgery (for example after bowel surgery)

anesthesia administered to a labouring mother or to someone after surgery. It is given into the epidural space at the base of the spine to numb the lower body. It reduces pain significantly by making the mother unable to feel contractions during labour and delivery.

epidural space

the space around your spinal cord


a flap of skin at the back of your throat


a brain disorder that causes you to have seizures


a short time when symptoms are worse






red rash on your face

erythrocyte sedimentation rate (ESR)

blood test

the rate at which red blood cells sediment in one hour, a test that looks for inflammation in your body

erythropoietin (EPO)

a hormone made by your kidneys

a hormone that stimulates your bone marrow to produce red blood cells. The hormone is naturally produced by your kidneys, and is also available as injectable medication


make worse, grow, increase


inflammation or swelling of your esophagus


swallowing tube

the part of your body that carries food or liquid from your throat to the stomach

estimated glomerular filtration rate (eGFR)

blood test to check how well your kidneys are working

blood test that uses a mathematical calculation to approximately measure your amount of kidney function


female hormone


someone who studies what is right and wrong

ethnicity (ethnic group)

a group people who identify with each other based on things like common ancestry, language, society, culture or nation


the cause of


plain to see, visible


make worse


when your symptoms get worse

examine, examination

when a doctor or nurse checks you over

test, look at

exceptional access program (EAP)

this program helps make it easier for patients to get medications not funded on the Ontario Drug Benefit (ODB) Formulary, or when no other medication will do. (A drug formulary is a list of prescription medications)

under special circumstances, some drugs require a doctor or nurse practitioner to apply for coverage of a drug that is not on the formulary.


too much


cut out, cut off, remove

executive function

a set of mental skills that help you get things done

examples of executive functions include your ability to:
• Initiate, plan and organize
• Set goals
• Problem solve
• Regulate your emotions
• Monitor your behavior

exercise induced bronchoconstriction

when the airways in your lungs get narrow while you exercise. It makes it harder to breathe


effort, work


cough, spit out


knowledge, skill, training

expiratory reserve volume (ERV)

how much air that you can still breathe out after a normal breath


come in contact with

expressing breast milk

removing breast milk from the breasts using a pump to store for a later feeding

expressive language

speaking, saying words or sentences

external fetal monitoring

 machine that monitors the progress of your fetus during pregnancy or when you are in labour. It records the fetal heartbeat and the mother's contractions.

extract, extraction

take something out, remove (for example a tooth)


arms, hands, legs and feet


to remove the endotracheal tube (airway tube)