Causes of Thinning Skin, Aging: As we grow older, our skin naturally loses collagen and elastin, leading to Thinning Skin. Sun Exposure: Chronic exposure to the sun can damage skin cells, causing thinning and premature aging. Genetics: Genetic predisposition may cause certain individuals to have naturally thin or sensitive skin. Medical Conditions: Certain health conditions such as diabetes or skin disorders can lead to thinning skin. Medications: Some medications like long-term topical steroid use can cause skin thinning.