13 Essential Medical Terms You Will See Everywhere
Have you ever listened to a doctor, read a
medical article, or even a prescription and thought to yourself, “What
do all of those Latin phrases and abbreviations mean?” I know I have for
years, and this curiosity really encouraged me to research some of
those confusing terms and shortenings once and for all and finally gain a
deeper understanding of my own health. We guarantee that you, too, will
learn some useful medical lingo from this article, and maybe even
bookmark it for future reference.
1. In vitro/ in vivo 
These terms are most commonly used to denote two different kinds of
studies, but they can also be used to describe a procedure, e.g.
in-vitro fertilization. The phrase in vitro can be translated as “in
glass” from Latin, and it refers to a procedure or study in a petri
dish, which is an experiment performed outside of a living organism.
In vitro studies often aim to examine the effect and safety of potential
medications on human or animal cells in a controlled environment, i.e.
the petri dish, usually before being replicated on live subjects. In
vivo means “within the living” in Latin, and it refers to a study or
procedure conducted on a live subject, be it a plant, lab animal, or
human. In vivo studies are considered more credible and are necessary to
access the full effect of a potential treatment, for example, on a live
organism.
2. Noninvasive/ invasive
When something, like a treatment, for example, involves entering the
human body with instruments, this treatment is said to be invasive. A
classic example of invasive treatment is surgery, but even an injection
is considered invasive.
Noninvasive, on the other hand, means that the treatment doesn’t require
entering the body with tools, and this treatment route is considered
simpler. Extra tip: another way to say that a treatment is simple and
noninvasive is to state that it’s conservative.
3. Acute/ chronic
Acute illnesses are such that begin suddenly but usually last for a
short time, i.e. usually up to a few weeks. For instance, one of the
most serious concerns in Covid-19 patients is the development of acute
respiratory distress syndrome (ARDS), a sudden respiratory failure
caused by widespread inflammation in the lungs.
Chronic conditions, on the other hand, develop slowly - from months to
years - and tend to get worse over time. Rheumatoid arthritis, an
inflammatory condition that develops over years or even decades, is a
classic example of a chronic condition.
4. Abbreviations referring to cardiovascular health
BP is short for blood pressure. BP is always shown in the form of a
fraction, e.g. 120/80 mm Hg. In this fraction, the systolic BP is the
top number, and the diastolic BP is the one on the bottom.
HR stands for heart rate, and it is measured in beats per minute (or
bpm). For example, the normal HR is between 60-100 bpm.
The two common shortenings for cholesterol measurements are HDL-C and
LDL-C. The former refers to high-density lipoprotein cholesterol or HDL
cholesterol, which is often called “good” cholesterol. LDL-C, on the
other hand, is the low-density lipoprotein cholesterol, which is also
often mentioned as “bad” cholesterol.
Also here are common shortenings of some heart conditions:
CHD—coronary heart disease
CHF—congestive heart failure
CAD—coronary artery disease.
5. Benign/ malignant
In medicine, the distinction between benign and malignant is most often
used to describe a tumor. The National Cancer Institute defines a tumor
as “an abnormal mass of tissue that results when cells divide more than
they should or do not die when they should.” Tumors are more common than
we think, and only some of them are harmful. In fact, every mole on
your body is considered a tumor.
To be able to distinguish these dangerous tumors from harmless ones, the
terms benign and malignant are used. Benign tumors are not cancerous,
and they don’t develop at all or grow very slowly. Malignant tumors, on
the other hand, are cancerous. These tumors grow fast and can even
spread to other parts of the body, which is why they are considered
dangerous.
There is also a third type - premalignant tumors - which are those that
are not dangerous yet but have the potential to become cancerous.
6. Abbreviations on prescriptions 
While reading a prescription, you may have come across a shortening that
starts with
q-. This is the abbreviation of the Latin word quaque that
means “each or every.”
Here’s what each specific abbreviation means:
qd—every day
qh—every hour
q2h, q6h, … etc, —every 2 hours, every 6 hours, …
qid—four times a day
qhs—every night at bedtime.
There are also a few abbreviations that don’t involve quaque, such as
these:
tid—three times a day, from the Latin “ter in die” meaning literally
“three times a day”.
bid—twice a day, from the Latin “bis in die.”
od—once a day, from the Latin “omne in die.”
A prescription will also usually tell you how to take the medicine. And
for this, there are separate abbreviations, here are a few:
po—by mouth
ac—before meals
pc—after meals
prn—as needed, whenever necessary.
7. Idiopathic
Unfortunately, medical science hasn’t yet been able to categorize every
health condition out there, and sometimes, the cause of a specific set
of symptoms is unknown or cannot be determined. When this is the case,
the condition is said to be idiopathic, or “relating to or denoting any
disease or condition which arises spontaneously or for which the cause
is unknown” according to the Oxford dictionary.
The term stems from the Greek idios "one's own" and pathos "suffering,"
which can be approximately translated as “a disease of its own kind.”
8. Etiology
The etiology of a certain health condition is a fancy word for its
cause. One could say, for example, that the etiology of an idiopathic
condition is unknown. The term is derived from the Greek word
aitiología, which means "giving a reason for something."
9. Abbreviations for ways to administer a drug
There are many ways a medication can end up
in your body, and each of these has its own abbreviation. You may be
already familiar with the IV - or the intravenous route - as it’s the
common term, but here are a few other shortenings:
PO—by the mouth.
SL—sublingual, medication given under the tongue.
IM—intramuscular, when medication is administered directly into a
muscle, like a vaccine shot.
INH—inhaled, like an asthma inhaler.
PR—rectally.
ID—intradermal, medication given under the dermis (top layer of the
skin).
10. Abatement
You’ve likely heard of the term remission, which stands for the
disappearance of the symptoms of a disease. But what is abatement? It’s
similar, but not quite the same. Abatement refers to the reduction in
the severity of symptoms. For example, allergy vaccines usually lead to
abatement but not the full disappearance of the allergy.
11. Miscellaneous abbreviations
Here are a few more useful abbreviations you could encounter in your
medical history, and what they mean:
FUO—fever of undetermined origin
FH—family history
Fx—fracture
V/S—vital signs
NKA—no known allergies
WNL—within normal limits.
12. Topical
Topical (or local) treatment or medication
is such that is applied to a particular area of the body as opposed to
the entire body. Most often, this refers to a medication in a cream or
ointment form that is intended to be used on the surface of the skin or
mucous membranes. For example, if you have an insect bite, you can apply
Panthenol creme topically (or locally).
13. Syndrome
The term syndrome is often confused with either symptom or disease, but
it’s neither of those things. While diseases or disorders both have a
definite and identifiable medical cause, a syndrome is a collection of
signs and symptoms that might not always have a definite cause. For
example, the common cold is a disease that is most commonly caused by
rhinoviruses, so it wouldn’t be correct to call the common cold a
syndrome.
Carpal tunnel, on the other hand, is called a syndrome because it
happens as a result of the compression of the median nerve in the wrist,
but it can be caused a few different things, including fractures, fluid
retention, diabetes, and even high blood pressure.