11 common causes of dry skin

A dry skin problem can be uncomfortable and even maddening. Your skin might feel tight and painful; it might look dull or red or flaky. Worst of all is the itchiness -- the sort of overwhelming itchiness that makes you feel like you're infested with fleas, that keeps you awake at night, miserably raking your skin with a back scratcher.
"Dry skin is extremely common," says Barney Kenet, a dermatologist from New York Presbyterian Hospital and Weill Cornell Medical Center. "There are probably close to 100 million dried out, itchy people in this country right now." And if the itching weren't bad enough, a dry skin problem can be more than just a superficial issue, experts say.
"Your intact, healthy skin is your body's primary defense against infection," says Claude Burton , professor of dermatology at Duke University School of Medicine. If you let your skin get dried out and cracked, you could be giving all sorts of nasty bacteria a way in. That can lead to more serious problems.
There are lots of good reasons to do something about your dry, itchy skin -- your looks, your health, and your sanity. So it's time to put down the back scratcher and really figure out what's really causing your dry skin problem.
Simple causes include harsh soap, itchy clothing, misusing moisturizer, and long, hot showers. But the medications you take -- and even medical conditions such as diabetes, psoriasis, hypothyroidism, and malnutrition -- can also cause severe dry skin. Read on to understand how and why these problems dry out your skin.

Understanding Dry Skin
Let's start with some skin basics. Normal, healthy skin is coated in a thin layer of natural lipids, or fatty substances. They keep in moisture, leaving the skin soft and supple.
What causes dry skin -- or xerosis, as it's known medically? Usually, something in the environment -- or something you're doing to your skin -- is stripping away these fatty oils, leaving your skin unprotected. Less often, the cause is internal; a health condition or genetic predisposition is making your skin dry out.
While patches of dry, itchy skin can appear anywhere, it's most common on the arms, hands, lower legs, and abdomen. Dry skin is often felt more than it's seen, but on some people it can be noticeable and embarrassing. For many African-Americans, dry skin is a special concern, since the flakes of skin can look gray, or "ashy," says Vesna Petronic-Rosic, assistant professor of medicine and director of the Dermatology Outpatient Clinic at the University of Chicago Medical School.
If untreated, dry skin can sometimes lead to dermatitis -- inflammation of the skin -- swelling, and infection. The good news is that just as most causes of dry skin are external, most cures for dry skin are external. With careful dry skin care, you can usually solve the problem.

--Dry Skin Problem: Misusing Moisturizer
If you've been contending with dry skin, you've probably already tried a moisturizer -- if not dozens. But while moisturizers are a crucial part of dry skin care, experts say that we don't always use them very well.
The biggest mistake we make is applying moisturizer on dry skin, when it's least likely to help. "You have to put on moisturizer when your skin is still damp," says Kenet, author of How to Wash Your Face. "That way, the moisturizer is trapping the moisture still on your skin." Your skin shouldn't be sopping wet -- just pat yourself dry with a towel and put it on. Let it soak in for a few minutes, and then towel off the excess, Kenet says.
You've also got to get the right type of moisturizer. Experts recommend that people with dry skin get mild moisturizers that have no perfumes. Often, the cheaper stuff you can get at the drugstore is better than the high-end products, Kenet says. The moisturizer must also be thick and greasy for good dry skin care.
Petronic-Rosic has a simple moisturizer test. "Put some of your lotion in the palm of your hand and flip your hand over," she tells WebMD. "If it runs or drips, it's not thick enough for dry skin."

Dry Skin Problem: Dry Air
"Dry air is probably the most common cause of dry skin, especially during the winter," says Kenet, "It draws the moisture right out of the skin." Dry skin during winter even gets its own name: winter itch.
While cold, harsh weather does dry your skin, the biggest problem in the winter lies indoors -- the dry heat churned out by your furnace. (During the summer, air conditioning can have a similar effect.) To counteract the dry heat, start with a moisturizer. Turning down the thermostat a bit in the winter can also help, Kenet says.
Other dry skin care tips include using a humidifier in your bedroom, and bundling up -- with hats, scarves and gloves, when you're outside. Petronic-Rosic recommends that people wear socks that go high up their shins during the winter. "Cold air can actually get under the pant leg and dry out the skin on the legs," she tells . "I see it all the time, but it's the sort of thing people don't think about."

Dry Skin Problem: Long, Hot Showers & Baths
Prolonged exposure to water -- especially hot water -- can wash away the natural oils that protect your skin. If you get out of the bath or shower and your skin feels tight, it's dried out.
So what should you do? First, choose showers over baths. But that's not all. If you're accustomed to waking up in the morning with a long, languid shower, dermatologists have some brutal advice: limit showers to a few minutes and skip the hot water.
"The water doesn't have to be cold," says Kenet. "But it should be lukewarm rather than hot." Kenet also recommends angling the shower head away from you while you shave or soap up. It's another way of reducing the time your skin is being pounded by the water.
Afterward, pat your body dry with a towel -- rather than vigorously rubbing it -- and put on a moisturizer right away.

Dry Skin Problem: Soap
"One of the biggest problems people have with dry skin stems from their soap," says Burton. Soap can quickly strip away your skin's protective oils, and we tend to use way too much of it.
"The average person who goes to school or work just doesn't get very dirty during the day," says Petronic-Rosic. "But [in the shower] many people scrub at their skin like it's the bottom of their shoes." Unless you're a child or a ditch digger, the only parts of the body that need any soap or cleanser at all are the face, hands, feet, groin and underarms. The rest of the body can usually just be rinsed off with water.
While our doctors -- and our mothers -- always told us to wash our hands frequently, that can also lead to trouble. Ironically, while done in the quest to rid ourselves of germs, excessive hand washing can dry out the skin and cause it to crack and bleed, making infection much more likely.
Many of us choose unwisely when we're in the soap aisle of the supermarket. We go for harsh soaps that generate lots of lather and leave us feeling squeaky clean. "The bubbling and lathering from soap removes the oils from the surface of the skin and dries it out," says Petronic-Rosic.
For dry skin care, look for milder, "fragrance-free" soaps. That's not the same as "unscented," which may still have perfumes, Kenet says. For many people with dry skin, the best choice is a mild, non-soap skin cleanser, experts say.
Whatever you do, don't use any harsh implements to wash yourself. "People will get these incredibly abrasive sponges and brushes," says Burton. "Sanding your skin is not a good idea."

Dry Skin Problem: Itchy Clothing
Kenet says that many people obstinately wear clothing that they find itchy. But no matter how much you might love the look of a sweater, it's not worth it if it's uncomfortable. "If a sweater is itchy when you try it on, it's never going to get any less itchy," Kenet says.
In fact, it might get more itchy. Dry skin is especially sensitive to contact irritants, so continually exposing your skin to uncomfortable clothing could make your skin drier and itchier, Petronic-Rosic says.
Go with clothes that feel comfortable the first time you put them on. "Instead of wool, choose cashmere if you can afford it," says Kenet. "But cotton is just fine." Make sure your clothing isn't too tight either, since chafing can also cause and irritate dry skin.

Dry Skin Problem: Medications and Drugs
A number of medicines have the side effect of drying out the skin. They include drugs for
High blood pressure, like diuretics Allergies, like antihistamines Acne and other skin conditions, like retinoids If you notice the onset of a dry skin problem after starting a medication, talk to your doctor. He or she may be able to help by changing the dose or switching the medication.

Dry Skin Problem: Medical Conditions
Usually, dry skin is caused by external factors. But sometimes, it can be a sign of a something going on internally, whether it's a natural physiologic change or an illness.
For instance, dry skin often develops when people get older, especially in women. "Changes in hormone levels can cause dry skin as we age," says Petronic-Rosic. As many as 75% of people over 64 have dry skin. Other people, regardless of age, are simply genetically prone to dry skin.
A number of medical conditions can result in dry skin. Some of the more common of these medical causes are:
Skin conditions, like eczema and psoriasis. While they usually need direct treatment, careful use of moisturizers often helps.
Diabetes. Fluctuations in glucose levels can lead to dehydration, and that dries the skin out. Given that diabetes can also slow healing and increase the risk of infections, it's especially important for people with this condition to keep their skin healthy.
Hypothyroidism. Low levels of thyroid hormone can reduce the amount of oil produced by your skin. As a result, skin becomes dry and rough and moisturizer is unlikely to help. Hypothyroidism is usually accompanied by other symptoms, like fatigue and weight gain, Kenet says.
Malnutrition. Not getting the nutrients you need can leave your skin dried out. One possible cause is an eating disorder. Other diseases, both minor and serious, can also cause dry skin problems. The best way to treat these cases of dry skin depends on the illness. Sometimes, getting medication for the underlying condition directly will resolve the dry skin. But in other cases, you might still need to follow some of the basic dry skin care tips outlined above. Ask your doctor for advice.

Getting Help for Dry, Itchy Skin
While dry skin can be a sign of these more serious health conditions, it's usually nothing more than run-of-the-mill dry skin -- regardless of how horrible it feels.
"I see a lot of people who are in so much discomfort from their dry skin that they think that they must be really sick," says Kenet. "But they're not, and it's actually so easy to help them."
So if your dry skin problem is making miserable, it's time to talk to a doctor. He or she can help you identify the causes and get you the treatment you need. Doctors can recommend medicine if you need it, which could include antihistamines for itchiness or prescription creams, including steroids.
"If you've been struggling with dry skin, and you've tried various things and none of them work, don't hesitate to see a doctor," says Petronic-Rosic. "There's just no reason to suffer when we can help in so many ways."