Sharing What I've Learned

Psoriasis is not contagious and is not caused by poor hygiene — it is a chronic inflammatory disease of the immune system, with cytokines like IL-17 and IL-23. On the established connection to inflammatory bowel diseases and on "leaky gut," still unproven as a cause, on Mediterranean diet, gluten, and weight — and on the important difference between medical treatment...

The skin on the feet is thicker and has no sebaceous glands — that is why heels tend to dry and crack. On hyperkeratosis, which is a defense mechanism and not an enemy, why we do not file everything away, how urea works at different concentrations, why we dry between the toes but do not apply heavy cream there —...

Sleep wrinkles have a real mechanical basis — compression and shear of the skin on the pillow for hours — but there is still no quality research proving that sleeping on the back prevents wrinkles. On the difference between friction and pressure, on when the back is actually not recommended (snoring, pregnancy, reflux), and why sleep quality matters to the...

SPF 50 filters about 98% of UVB radiation — but only under laboratory conditions and at the standard quantity of 2 mg per cm², and it does not last a whole day. Why we reapply every two hours and immediately after swimming and toweling, what "water resistant" really means (40 or 80 minutes), and why even shade and clouds do...

When we walk into a supermarket and reach the cleaning products aisle, it is hard not to be impressed by the number of products — every surface seemingly has its own product, and every product another promise. But does every surface at home need to be disinfected? Does a strong smell of cleaning product indicate cleanliness? For most routine cleaning...

After a new haircut something changes in how we feel, although nothing essential changed in our lives. On habituation — why the brain gets used to our look — on self-perception theory and on Enclothed Cognition, whose research is not uniform, and why the important question is not what we change, but why.

In most cases dry heels are a local matter — skin structure, friction, and care habits — and extra drinking will not fix them. But sometimes the dryness connects to a wider picture: thyroid underactivity, diabetes, or Moccasin-type fungal infection that looks exactly like dryness. How to distinguish, and which signs do justify a medical examination.

A scratch that used to vanish in two days lingers for weeks today — and it is not imagination. On the four stages of wound healing, on Immunosenescence and Inflammaging, on estrogen after menopause, and on what really helps: sufficient protein, vitamin C from nutrition, sleep, and movement in the right dose — and when slow healing is no longer...

The word Fragrance hides a whole mixture the manufacturer is not required to detail — but that does not make every scented product dangerous. On contact allergy that can develop even after years of use, on phthalates and what science really knows about hormones, on the difference between Fragrance-Free and Unscented, and why a natural essential oil is not necessarily...

That tight, squeaky feeling after washing isn't cleanliness — it's a damaged barrier. Why the first rule of keeping skin young is what you wash it with.