Why do people have dry skin?

Meds. I completely agree with dr. Vuguin and please note that cholesterol lowering medications may also dry out skin. Simple at home steps include avoiding harsh soaps. I recommend cerave or cetaphil cleanser to growing, axilla and feet. Only water elsewhere. Use cream moisturizer (not lotion) immediately after showering to seal in moisture. Take fish oil supplement. If that fails, see a dermatolo.
Multiple reasons. Could be hereditary, aging, as natural skin oils diminish, medical conditions such as asthma or thyroid disease. Daily skin care habits such as washing with harsh soaps, can also cause or worsen dry skin.