Aging skin tends to be drier, and the same goes for nails. A lack of moisture can make the nail plate more brittle and emphasize any natural ridges. Regular exposure to water, soap, and cleaning chemicals can deteriorate this dryness.
Nutritional Deficiencies

Low levels of crucial nutrients like biotin, iron, zinc, or magnesium can cause weaker, ridged nails. Since metabolism and nutrient absorption may diminish with age, deficiencies become more likely after 40.
Health Conditions
In some cases, vertical ridges may imply health issues such as poor circulation, thyroid imbalance, or even rheumatoid arthritis. If you spot other symptoms like fatigue, brittle hair, or changes in skin texture, it’s worth visiting a doctor.