There are two categories of skin care issues, those affected by genetics and those affected by the environment. Patients often don't understand the difference between these two categories which leads to incorrect product choices which only further exacerbate whatever issue it is they're dealing with.
Take for example dry skin vs. dehydrated skin. Dry skin is genetically predetermined and is characterized by insufficient oil gland activity. Dehydrated skin is characterized by lack of moisture due to such factors as climate and over cleansing. So even oily skin types can suffer from dehydrated skin.
If your skin is dehydrated due to environmental causes, look for moisturizing products that contain humectants to seal the moisture in, and hydrating agents to increase the water content in the epidermis. Some examples of ingredients to look for include hyaluronic acid, panthenol, glycerin, aloe, and glycolopids.
If your skin is dry due to genetic causes, look for moisturizing products that contain emollients in addition to the humectants described above. Examples of emollients include shea butter, squalane, vitamin E, allantoin, and ceramides.
If you're not sure if you're skin issues are a result of the environment or your genes, your aesthetician or dermatologist will be sure to provide a proper diagnosis and help you to choose the most effective regimen for your skin's needs.