We’ve all been to the doctor’s office and felt like we left with more questions than answers, or scrolled past a video on social media packed with big claims about health topics that don’t quite add up.
Part of what can be so confusing about health is the varied terminology that people often use incorrectly, especially if they’re not health care providers or another type of medical professional.
That’s why Dr. Cedrek McFadden, board-certified colorectal surgeon, stopped by the TODAY show to break down some of the words and phrases that he frequently sees being used incorrectly and why it’s important to understand their actual definitions.
Infection vs. InflammationInfection: when germs, like viruses, bacteria, fungi or parasites, cause an illnessInflammation: the body’s response to injury or an infection
“These words are often used like they mean the same thing, but medically they are different,” McFadden says. “Inflammation can happen with infections, but it can also happen without germs being involved at all.”
Conditions like arthritis, allergies, gout, autoimmune diseases and even an intense workout can trigger inflammation, he adds.
The type of infection or injury will dictate the proper treatment more than the presence of inflammation itself. “What doctors pay closer attention to is fever, worsening redness, drainage, severe warmth or symptoms spreading quickly,” McFadden says.
Screening vs. Diagnostic TestsScreening tests: done before symptoms appear with the goal of prevention or finding disease early, such as mammograms or prostate specific antigen (PSA)Diagnostic tests: done because of the presence of symptoms, abnormal labs or another medical concern that already exists, such as CT scans and biopsies
“Patients often think a test is just a test, but why the test is being ordered matters,” McFadden explains. “A colonoscopy may look exactly the same to the patient, whether it is screening or diagnostic, but medically those are two very different conversations.”
Patients will often assume because they had a negative screen that they don’t need to worry about any symptoms that may pop up relating to the condition they tested negative for, McFadden says. But it’s still important to investigate possible causes of any concerning symptoms as early as possible.
Allergy vs. Side EffectAllergies: the immune system’s reaction to a triggerSide effects: a known but unintended outcome of a medication or other treatment
“People often describe any bad reaction to a medication as an allergy, but that is not always accurate,” McFadden says.
Medication side effects commonly include nausea, drowsiness or upset stomach, while allergies usually result in hives, swelling, wheezing or trouble breathing.
It’s important to known the difference because if you have an allergy to a medication, it will affect your future treatment options, and you don’t want to have these limitations unless it’s necessary.
“Serious allergic reactions should never be ignored,” McFadden adds.
Infectious vs. ContagiousInfectious: an illness caused by germsContagious: the illness can spread to others
While many illnesses, like COVID and influenza, are both infectious and contagious, not every infectious disease is both.
“For example, tetanus is infectious because bacteria cause it, but it does not spread from person to person,” McFadden explains. “Understanding the difference can help people better interpret public health warnings, isolation recommendations and infection risks.”
Benign vs. MalignantBenign: a growth that is not cancerous (but can still have negative health effects)Malignant: a growth with cancer cells that can spread
“Some benign growths can still cause symptoms depending on where they are located or how large they become,” McFadden says.
Acute vs. ChronicAcute: a health problem that started suddenly or has been present for a short periodChronic: a health problem that has been around for months or years
“One of the biggest misconceptions is that acute means serious and chronic means not serious. That’s not necessarily true,” McFadden says.
“For example, a sore throat that started yesterday is acute. High blood pressure is chronic. Diabetes is chronic. Heart disease is often chronic. In fact, many of the conditions that have the biggest impact on our long-term health are chronic conditions.”
People are usually more likely to seek medical care for an acute condition because it showed up suddenly, whereas chronic issues just feel like part of everyday life, making them easier to overlook, McFadden explains.
But, “the key thing to remember is that (“acute” and “chronic” only) tell us about time, not importance,” he adds.