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

Thank you!


stomach, stomach area, belly, tummy

abdominal aortic aneurysm (AAA)

bulging of the large artery that carries blood from your heart to your abdomen and lower parts of your body

abdominal paracentesis (paracentesis)

when a needle is inserted into the skin below your belly button to remove extra fluid from your abdomen.

This is done too take out a small amount of fluid for lab testing or to take out a large amount of fluid that might be causing you pain


to move your arm or leg away from your body


cut, scratch, scrape


sore, wound, infection

a tender swollen lump caused by an infection

absorb, absorption

take in, soak up


don't, don't use, don't have, go without


usable, available, on hand, understandable

accessory muscle

muscles around your chest that help you breathe


go with, take with


do, finish


add, gain, build up


add up, gather, collect


true, right, correct

acellular vaccine

a vaccine that has part of the virus in it

achilles tendon

attaches your calf muscles to your heel bone. You use this tendon to jump, walk, run and stand on the balls of your feet

achilles tendonitis

pain in your achilles tendon


too much acid in your blood


get, gain

acquired immune deficiency syndrome (AIDS)

a disease that makes it hard for your body to fight off infections and other diseases


begin, start

active immunity

being able to fight off a disease when you have had it before

active labour

part of the first stage of labour

active labour happens when the cervix dilates from three to seven centimeters. Active labour lasts an average of two to four hours. The contractions during active labour are strong, long (40 to 60 seconds each), and frequent (three to four minutes apart)

activities of daily living (ADLs) and instrumental activities of daily living (IADLs)


things you do to take care of yourself such as bathing, dressing, eating etc.

things you do every day for your personal care


things you do for independent living such as shopping, cooking, driving etc.


treatment that uses thin needles. They are put into your skin at certain places on your body to help you feel better


serious, new, sudden start

(of a disease or its symptoms) of short duration but typically severe

acute coronary syndrome (ACS)

  chest pain or a heart attack

acute inpatient facility

a place, such as a hospital, where someone gets care for a short period of time

acute kidney failure

when your kidneys stop working suddenly

rapid, sudden loss of kidney function, often reversible


habit forming


extra, added, more


talk about, discuss


enough, the right amount


stick with, follow


beside, next to, near, touching

adjunctive therapy

an extra treatment that is used to help your main treatment


something added to a vaccine, chemotherapy to make it work better

adding radiation treatment to surgery


give, manage, take care of

adrenal gland

an organ on the top of each kidney that makes many hormones and sends them out into your body

adrenaline (hormone)

a hormone (chemical) made by your body when you're under stress or have certain medical conditions.

Adrenaline can increase blood pressure, heart rate and breathing

advance care plan

a summary of your wishes or instructions about the kind of care you want or don’t want. This plan is for a time when you can’t speak for yourself. An advance care plan can be written down or you can tell your wishes to someone, such as your substitute decision-maker. If a health care provider asks your substitute decision-maker to make treatment decisions for you, this plan can help them do that. It is different from making plans for your finances, property, estate, will or funeral arrangements.

advance directives or living wills

papers that help you tell others your wishes and decisions ahead of time

papers that list your wishes about your end-of-life health care

a voluntary written document about your expressed wishes. It is to instruct and guide your Substitute Decision Maker about your wishes for the personal and health care you would like to receive (or not). This is not a legally binding document in Ontario.


helpful, useful


bad, dangerous, hurtful, harmful

adverse event

a bad reaction, something that you didn't expect to happen


tell, warn, say


taking charge, support, support person


needs oxygen to live

aerobic exercise

slow and steady exercise, like walking, running, biking and swimming


spray, mist


yes, positive


others, other group, partner


make worse


altogether, added together, combined


anxiety, restlessness, nervousness


sickness, illness, health problem, complaint


carried through the air


air moving through your body

airway remodelling

when your airways change shape because of injury


You may here different kinds of alarms in the hospital

Monitor alarms will sound when heart rate, respiratory rate or oxygen saturation fall outside an acceptable range

Medication pump alarms will sound to notify staff that a treatment or infusion is complete

Ventilator alarms will sound to notify staff of a disruption in the circuit or a change in the delivered support. Staff in the NICU/PICU set alarms to go off at the slightest change and before a serious problem arises. This may cause false alarms at times, but it allows us to observe your child closely. Alarms may also be observed from the nursing station.

Bed and chair alarms will sound to notify a healthcare provider of activity of a patient in their bed/chair

Patient safety alarms sound to notify healthcare providers that there is motion through the doorways.


having to do with food and how it moves through your body


when your blood doesn't have enough acid


things like pollen or mold that can cause your body to have a reaction, like sneezing or a rash

allergic rhinitis

hay fever


allergy doctor, a doctor that takes care of people with allergies


reaction to certain things such as some kinds of food or pollen, itch, rash, hives, breathing problems


ease, decrease, lessen


divide, give out, ration out


disease that causes hair loss from some or all areas of the body



alternate level of care (ALC)

when a hospital patient is well enough to leave the hospital


tiny air bags/sacs in the lungs, these bags help bring oxygen to the blood


silver-coloured fillings in your teeth


put together, join, combine

ambu bag

an inflatable bag connected to oxygen that a doctor, nurse or respiratory therapist can use to help you breathe


walk, move around


can walk, mobile, able to move about


make better


change, adjust, fix

amino acid

what proteins are made of


memory loss, not being able to remember


A test for your baby's health that is done before it is born. Your doctor will take a small sample of amniotic fluid from around your baby

A diagnostic test to determine whether the fetus has any abnormalities. Performed anywhere between weeks 14 and 20 of pregnancy (though more commonly between weeks 16 and 18), amniocentesis tests the fluid inside the amniotic sac that surrounds the baby. The fluid, which contains the baby's skin cells, is drawn from the uterus through a hollow needle inserted through the expectant mother's abdominal wall and is tested for chromosomal abnormalities, genetic abnormalities, or other diseases.

amniotic fluid

water, fluid around your unborn baby in your uterus (womb)


a small glass or plastic container that holds a drug or other liquid


an operation to remove part of, or all of one of your limbs

the surgical removal of all or part of a limb or extremity

amyotrophic lateral sclerosis (ALS)

Lou Gehrig's disease

motor neuron disease


without oxygen


not being able to feel pain 

any intervention that reduces the sensation of pain.


pain killer, pain reliever

a medication that reduces the feeling of pain without loss of consciousness.


look at, study, examine


serious allergic reaction, shock


about the anatomy of the human body


low iron, low blood count

a medical condition in which the number of red blood cells (your blood count) is low


when you are not aware of pain, for example, when you have been given medication before an operation or procedure


a doctor trained in giving anesthetics during surgery and caring for those who have been given an anesthetic

a doctor who is dedicated to total care of a patient undergoing surgery and the relief of pain. Total care includes preparing you for surgery, being responsible for pain relief in the early recovery phase as well as treating complications that may result from the anesthetic

anesthetic (general)

a medication or drug that puts you to sleep, or puts you "under"

a medication that produces a loss of sensation, either partially or completely

medication that makes a person unconscious and unable to feel pain. General anesthesia is sometimes used for emergency caesarean sections.

anesthetic (local)

a medication or drug that numbs an area of your body


bulging of a blood vessel wall


chest pain, chest pressure or heaviness

angio seal


a vascular closure device, also referred to as a plug, placed in the groin to seal the puncture site after an angiogram


swelling of your skin, or swelling inside your body usually because of an allergy


An x-ray test that uses a special dye and camera to take pictures of the blood flow in an artery or vein. An angiogram can look at the arteries or veins in your heart, head, arms, legs or belly.

A test that takes x-ray pictures of the coronary arteries and the vessels that supply blood to the heart. During an angiogram, a special dye is released into the coronary arteries from a catheter (special tube) inserted in a blood vessel. This dye makes the blood vessels visible when an X-ray is taken. Angiography allows doctors to clearly see how blood flows into the heart. This allows them to pinpoint problems with the coronary arteries.

Angiography may be recommended for patients with angina (chest pain) or those with suspected coronary artery disease (CAD). The test gives doctors valuable information on the condition of the coronary arteries, such as atherosclerosis, regurgitation (blood flowing backwards through the heart valves) or pooling of blood in a chamber because of a valve malfunction.


Angioplasty opens blocked arteries so that blood can flow to your heart. It is done by putting a thin tube (catheter) in through a small puncture in your arm or leg artery up to your heart. A balloon is inflated and then removed. This opens the artery.

Angioplasty is a procedure to widen narrowed or obstructed arteries or veins. An empty, collapsed balloon, known as a balloon catheter, is passed over a wire into the narrowed locations and then inflated. The balloon forces expansion of the narrowed area within the vessel and the surrounding muscular wall, opening up the blood vessel for improved flow, and the balloon is then deflated and withdrawn. 

angiotensin converting enzyme inhibitor (ACEI)

medication for high blood pressure

a medication used for cardiovascular protection and to lower blood pressure

angiotensin receptor blockers (ARB)

medication for high blood pressure

a medication similar to Angiotensin Converting Enzyme Inhibitor (ACEI) which provides blood pressure management and cardiac protection

ankle brachial index (ABI)

a quick way to test to see if the arteries in your legs are blocked. It compares the blood pressure in your ankle to the blood pressure in your arm

a measurement that looks at the blood flow in your leg.  A blood pressure cuff is attached to your leg and a reading is made, then a blood pressure reading is obtained in the arm


defect, change, difference, unusual, exception


not hungry, eating disorder


when a part of your body isn't getting enough oxygen


something, often a medication that stops or reverses another action


happens before something


before birth

occurring or formed before birth; prenatal.



anti-cancer medications

medications that are used to fight cancer


a medication that brings down swelling or pain

anti-rejection medications

when a new organ is placed inside your body (transplanted) your body's immune system thinks the organ is foreign tissue and tries to reject it. Anti-rejection medications help to stop your body from rejecting the organ.

medications given after an organ transplant to lower the body's immune system so that the transplanted organ is not rejected


blood thinner

a medication that prevents and treats blood clots, an example is Warfarin (Coumadin)


medications used to stop seizures


medications or other therapy to help ease depression


medication that helps lower blood sugar, used to treat diabetes


medication that lowers the amount of urine your body makes


medication that can stop poison from doing harm to your body

antiemetic (anti-nausea medication)

medication that stops or eases the feeling of nausea and the chances of throwing up


medication used to stop seizures


medication that stops skin infections caused by fungus


germ, bacteria, virus, something in your body that helps it fight disease


medication used to stop allergies


medication used to help lower high blood pressure

Antimicrobial Stewardship Program (ASP)

a program that makes sure you get the right antibiotics, when you need them

a patient safety practice to ensure optimal antibiotic use. This reduces the risk of being exposed to resistant bacterial infections.


something that helps the cells in your body to stay healthy


a medication that stop blood cells called platelets from sticking together and forming a clot

a medication that decreases platelet aggregation and helps prevent clots, an example is aspirin (ASA)


medication used to stop itching


medication used to treat some mental illnesses


something used to slow down the growth of germs on your skin


medicine that fights viruses


fear, worry


the largest artery that carries blood from your heart to other parts of your body

aortic valve

Your heart has four main valves - two on the left and two on the right.  The aortic valve is one of the valves on the left side of your heart. It controls the flow of blood from your heart to the rest of your body

aortic valve disease

a heart valve problem that affects blood flow through your heart

when a valve does not close tightly enough or does not open wide enough. It causes blood to flow into your heart at times that it shouldn't

aortic valve replacement (AVR)

a type of open heart surgery used to treat problems with your heart's aortic valve

aortic valve stenosis

a problem where one of your heart valves doesn't open as far as it should

this decreases blood flow from your heart to your body. It is a type of aortic valve disease

apgar score

A newborn baby's first test. Given one minute after a baby is born, then again five minutes later. The Apgar assesses the newborn's appearance (skin color), pulse, grimace (reflex), activity (muscle tone), and respiration. A perfect Apgar score is ten; typical Apgar scores are seven, eight, or nine.

aphasia, aphasic

trouble talking or understanding words, sometimes includes trouble reading and writing

aplastic anemia

an illness that happens when your bone marrow doesn't make enough red blood cells


pauses in breathing when you sleep

pauses in breathing that last 20 seconds or longer, may be associated with colour change and low heart rate. Infants may be described as apneic


swelling and infection of your appendix


about, guess, around, near, bring together


condition where your brain and muscles don't "talk" to each other properly. This is caused by damage to the brain.

apraxia makes it hard to move or complete a task when asked, even though:
• You understand what's being asked
• You are willing to do the task
• Your muscles work properly
• You may already know how to do the task



arrhthymia (dysrhthymia)

when your heart rate isn't regular


irregular heart beat, when your heart doesn't have a steady beat

an abnormal heart beat or rhythm because of an electrical problem in the heart 

arterial blood gas (ABG, blood gas)

blood test to see how much oxygen is in your blood

blood test that is done to determine the levels of oxygen, carbon dioxide and bicarbonate that is in the blood. This helps determine how much help the infant may need to breathe. This test may be done via artery, vein or a capillary sample.

arterial Line

catheter (tube) that goes into the artery in your arm or leg to monitor your blood pressure and take blood samples

flexible catheter inserted into an artery of the arm or leg to allow the continuous monitoring of blood pressure and the sampling of arterial blood to ensure adequacy of oxygen and carbon dioxide levels

arteriosclerosis or atherosclerosis

hardening of your arteries


a special tube that carries blood through your body

a blood vessel that takes blood from your heart to other parts of your body


pain in your joints


a disease of your joints that causes swelling, pain and stiffness

arthroplasty (joint replacement surgery)

an operation where parts of your joint are repaired or replaced with artificial parts



an operation where a tiny camera is put into your joint to see inside it and repair it


find out, learn

ascorbic acid

vitamin C

asepsis (aseptic)

free of germs or infections


suffocate, choke, smother


to breath in food or fluid to your lungs

take out fluid or tissue to test


to breath in food or fluids into your lungs, fluid in your lungs



lab test


review of your general condition

test, interview

evaluation of a baby's general condition


asthma action plan

a plan you write with your doctor or nurse practitioner. It lists the medications you take. It tells you what to do if your asthma gets worse or you have an asthma attack


when you are sick, but don't feel or look sick, without symptoms

ataxia, ataxic

clumsy movement of your arms, legs or body


hardening of your arteries, clogged blood vessels


about the part of your heart that blood flows into

atrial fibrillation (AFib)

when your heart beat is not regular, sometimes your heart may beat too fast.

an irregular heart rhythm in the upper chambers of your heart 


a part of the heart that blood flows into

the upper chamber of each half of the heart. The right atrium receives deoxygenated blood (blood with the oxygen removed) from the entire body (except lungs)


waste away, weaken, shrink




go to, show up, see to, manage, listen to

Attending Physician


staff physician who oversees your medical care

attention deficit disorder (ADD)

a problem that makes it hard to pay attention and sit still. It can make learning harder


unusual, uncommon, out of the ordinary, not normal


someone who tests and treats people with hearing problems and other ear problems


the study of hearing and ear problems


about hearing

augmentation of labour

if  your labor isn't progressing very well, your doctor may try to help it along (or "augment" it) by doing something to stimulate your contractions

what is done to help labour that has begun naturally to progress more rapidly. Often, Pitocin (a synthetic form of the hormone oxytocin) is used to make contractions stronger or to rupture the membranes.


a feeling you might have before a seizure or migraine headache--can be something you hear, see, taste or just sense

auscultate (auscultation)

when someone listens to the sounds inside your body, lungs, stomach


brain disorder that can make it hard for someone to make sense of the world, talk to others, or to understand what others are thinking

autoimmune disease

disease that makes your body attack itself

automated or continuous cycler peritoneal dialysis (APD, CCPD)

a type of kidney dialysis

form of continuous peritoneal dialysis in which a machine called an automatic cycler performs regular exchanges throughout the night

autonomic nervous system

this controls our how your internal organs work, such as how your heart beats and your lungs breathe


free, by itself, independent

autonomy (autonomous)

free, by itself, independent


when a doctor examines a dead body to find the cause of death




armpit, underarm

axillary temperature

temperature that is taken by placing thermometer under your arm