Unless a major breakout situation crops up overnight, you probably aren’t thinking about your skin constantly during the day. And yet, your skin is hard at work 24/7, under-the-radar repairing and protecting your entire body — organs, bones, and beyond — from anything life may throw your way. Think about it: your skin barrier, which is the outer, topmost layer, essentially acts as a security guard. It controls what comes in, halting potential problem-posers like pollution, and defends what’s already inside, like the cells that regenerate on repeat to give you a brighter, healthier complexion. So really, you can thank your skin barrier for all of your good skin days (and blame it for any major flareups or sudden freak-outs).

All too often, people assume they have sensitive skin when, in reality, they’re dealing with a damaged skin barrier. Worse yet, it doesn’t take very much for your skin barrier to become compromised. “Airborne pollution, UV sunlight, cigarette smoke, flying for more than six hours, washing hands too frequently, physical and emotional stress, or even a lack of sleep can damage the barrier,” notes Carl Thornfeldt, a dermatologist and the founder of Epionce, a skincare line he designed specifically to improve his own barrier function and treat atopic dermatitis when nothing else did the trick. Aggressive products can also strip the skin of its essential lipids, allowing for what’s called transepidermal water loss, which is basically a fancy scientific term for the dehydration, redness, and sensitivity associated with barrier damage.

If you haven’t really been exposed to any of those factors, you may naturally have a weaker barrier. “Those with rosacea and very dry skin, and those that live in harsh climates are more prone to barrier issues,” says Rebecca Kazin, a dermatologist at the Washington Institute of Dermatologic Laser Surgery and the Johns Hopkins Department of Dermatology. Your individual skin tone also plays a role in the effectiveness of your skin’s barrier function — those with darker skintones have to work harder to keep their barrier intact. If you start to notice your skin has a flaky texture, yet you have to keep blotting papers on hand at all times to mop up oil, your barrier functioning may not be in full-force. “Scaling, inflammation, and the overproduction of oil is the body’s way of trying to protect itself,” Dr. Thornfeldt says. “A healthy barrier means healthy skin.” Dehydrated, itchy, and sensitive, irritated skin are also major signs of barrier impairment. “Irritants that your barrier would otherwise block out are able to permeate the barrier when it’s damaged,” Dr. Kazin explains. “So the skin becomes ‘sensitized,’ and those with sensitized skin can have similar symptoms to those with sensitive skin.” There is a big difference, though. Sensitive skin is a skin type, whereas sensitized skin is a direct result of barrier damage.

So how do you repair a barely-functioning barrier?

Re-assess your beauty routine.You may not know it, but you could potentially be doing damage to your barrier all on your own. Basic habits like over-exfoliating with harsh scrubs (especially the ones formulated with jagged pieces), or using a face brush too often can weaken your skin’s defense system. Even some of your skincare staples could be to blame — for example, anything formulated with highly active ingredients like salicylic acid can further strip sensitized skin. You should also beware of foaming cleansers, which steal moisture from your skin. Instead try Pai Camellia & Rose Gentle Hydrating Cleanser. And even though you may love the silky-soft feel of any skincare or makeup products with silicones, they’re not doing your barrier any favors. “Silicones, including dimethicone, produce emollience, and tricks you into thinking your skin is moisturized,” Dr. Cornfeldt warns, “but any highly emollient products will not moisturize skin. Emoillience makes skin feel softer, but not hydrated.”