What Is in Air Freshener? Chemicals & Health Risks
Air fresheners contain fragrance chemicals, solvents, and unlisted hazardous compounds that may affect your health — including so-called natural options.
What Is an EtOH Test? Alcohol Screening Explained
EtOH is medical shorthand for alcohol. Learn how alcohol screening tests work, what your results mean, and when doctors use them.
What Is Polyester Made Of: From Crude Oil to Cloth
Polyester starts as crude oil and ends up in your shirt. Here's how that chemical journey works and what it means for the environment.
What Is a Phenotype? Definition and Examples
A phenotype is how your genes and environment combine to shape who you are — from eye color to disease risk. Here's what that means for your health.
What Is a Shunt Surgery? Types, Risks, and Recovery
Shunt surgery drains excess fluid to relieve pressure in the brain or body. Learn how it works, what recovery looks like, and when revisions may be needed.
What Is an ELT in Aviation and How Does It Work?
An ELT is a crash-activated distress beacon that helps rescuers locate downed aircraft. Here's how it works and what pilots need to know.
What Makes Sciatica Worse? Triggers and Habits
From sitting too long to stress and poor footwear, learn which everyday habits and triggers can make sciatica pain worse.
Where Are Ponds and Lakes in Your Community?
Learn how to find ponds and lakes near you using free maps, state wildlife resources, and simple tips for spotting both natural and engineered water bodies.
What Is Advanced Gum Disease? Symptoms and Treatment
Advanced gum disease can affect your overall health, not just your teeth. Learn the signs, how it's treated, and what recovery looks like.
What Is Oil Made Of? Crude Oil to Cooking Oil
From ancient fossils to your kitchen pantry, oils share more chemistry than you'd expect. Here's what they're actually made of.