What Are the Causes of Dry Skin?

Dry skin is a skin issue that affects people in varying degrees. It usually isn't a serious issue. Some people occasionally have mildly tight or flaky skin that goes away with a good moisturizer. Others have flaking and itching so bad that it's physically uncomfortable and affects their ability to sleep.

Many of the causes of dry skin listed below affect the stratum corneum: the top layer of the epidermis. The stratum corneum works like plastic wrap around the body by keeping harmful substances and germs out and keeping water and oils in, making skin soft and supple.

Before you reach for your favorite moisturizer, see if any of these seven causes could be to blame for your dry skin.

Age

Middleage woman, skin close-up — RunPhoto/The Image Bank/Getty Images

Older age is one of the most common causes of dry skin. As we age the epidermis becomes thinner and the stratum corneum can't retain as much water as it once could. Many people start getting dry skin in their 50s; by our 60s, almost everyone is experiencing some degree of dry skin. Unfortunately, it's unavoidable.

Climate

USA, New Jersey, Jersey City, Woman in snowfall — Tetra Images/Creative RF/Getty Images

Climate has a huge impact on skin. In general, skin is at its driest during the winter when the temperature and humidity levels drop, and cold winds suck moisture out of the skin. Cold weather also calls for heat and more time spent indoors, which also dries out skin. Central heat, space heaters, and fireplaces all wreak havoc on the skin's moisture levels.

Conversely, even weather in warm areas can cause dry skin. For example, desert regions might have warm temperatures, but they also have low humidity levels, which strips the skin of moisture.

Sun Exposure

Black woman leaning out car window — Adam Hester/Blend Images/Getty Images

Sun exposure in any climate can dry out the skin. UV rays penetrate deep below the skin's surface, which also creates wrinkles and sagging in addition to dryness. The heat of the sun dries out skin by reducing its natural oil levels.

Water

Woman washing face with wash cloth over sink, side view — Karen Moskowitz/Stone/Getty Images

Water is good for the skin. That is when you drink it. Water can actually dry out the skin because when it evaporates, it takes the skin's natural oils with it. Swimming in a pool, especially one that's heavily chlorinated, and taking excessively hot baths, can seriously dry out skin. The more frequently skin comes in contact with water and the hotter that water is, the more oils leach out, leaving skin with that dry, tight, uncomfortable feeling.

Soaps and Detergents

The woman is washing her face. — Michael H/DigitalVision/Getty Images

Soaps and detergents cause dry skin in the same way water does. They surround the water molecules in the skin and take them with when they're rinsed off. Certain soaps and deodorants are typically the most drying. A good rule of thumb to follow is that any bar soap is going to be harsher on the skin than a liquid soap. Some liquid body cleansers actually help moisturize the skin.

Medication

Hispanic girl putting on acne cream — KidStock/Blend Images/Getty Images

There are certain medications that cause dry skin by reducing the stratum corneum's water levels, making it porous and leaky. Some common medications that cause dry skin are diuretics like hydrochlorothiazide or furosemide, Retin-A, cholesterol medication like pravastatin and simvastatin, and Accutane.

Diseases & Skin Conditions

Mid adult woman applying lotion on her legs — Stock4B/Stock4B/Getty Images

Certain diseases and skin conditions cause dry skin for different reasons. Dry, flaky skin is the hallmark symptom of two common skin diseases: atopic dermatitis and psoriasis. Malnutrition, kidney disease, and dialysis can all cause dry skin because they can deprive the skin of essential vitamins.

_Sources:

_{Misery, L. “How the skin reacts to environmental factors.” Journal of the European Academy of Dermatology and Venereology. 21 Suppl 2(2007): 5-8.}

_{Pons-Guiraud, A. “Dry skin in dermatology: a complex physiopathology.” Journal of the European Academy of Dermatology and Venereology. 21 Suppl 2(2007): 1-4.}

_{http://www.mayoclinic.org/diseases-conditions/dry-skin/basics/definition/con-20030009}