May 29, 2009 -- Whatever fashion experts might say about UGG-style boots, skinny jeans with thongs peeking above the belt or handbags with tiny dogs nestled in them, some doctors and researchers are now weighing in for the public good.
Popular fashion choices can actually cause serious medical conditions and nasty infections, doctors say.
Skinny jeans in the 70s used to cause some emergency room visits to remove the fabric. The new and improved stretch fabric in today's skinny jeans has led to an uptick in nerve damage.
ABC News talked with experts researching and treating these problems for advice on healthy fashion choices, and to uncover myths about clothing with a bad reputation for your health.
Are Skinny Jeans Dangerous?
Skinny jeans have the reputation of being painful on egos, full stomachs and, occasionally, hard on the eyes.
But Dr. Orly Avitzur, a neurologist at Yale University, has found yet another way skinny jeans have been hurting people in the long-term, meralgia paresthetica.
The condition starts when tight-fitting clothing compresses a nerve in the groin close to the skin's surface. Put enough pressure on it, and the whole nerve can begin to react, running from your groin, to your outer thigh and down toward the knee.
"It can feel anywhere from numb to prickly, to a tingle, to burning, to painful or irritating," Avitzur said.
What's worse, even if people throw out the skinny jeans, their pain may linger. "It can take some time for it to dissipate? weeks or months even sometimes, if the damage is extensive," Avitzur said.
Skinny jeans-bearing youth aren't the only ones to suffer from this painful condition. Avitzur said pregnant women and obese people can also suffer from nerve compression. Across the population, Avitzur estimates 4 in 10,000 have suffered.
But Dr. Elizabeth Steiner in Oregon has seen other problems from pesky skinny jeans in her female patients.
Can Thongs Cause Infections?
Some think they're sexy, some don't, and some people still think you're talking about shoes. But whatever a thong means to you, doctors are questioning their contribution to infections.
Women might be at risk for infection, "When you wear thong underwear, or tight underwear or regular underwear and very, very tight pants," said Steiner, an associate professor of family medicine at Oregon Health and Science University in Portland.
Steiner said that when a person uses the toilet, it's normal for bacteria "to populate" around the anus.
But, in women, "our vaginas, our anuses and our urethras are very close together," Steiner said.
When a woman wears tight jeans, tight underwear, or even thongs with tight jeans, Steiner said it can set up just the right conditions to move the bacteria from the anus, where they normally live, up to areas where the bacteria doesn't belong.
"The friction can move bacteria along the perineum up to the vagina and to the urethra," she said. "Bacteria are sneaky."
Then, because women's urethras are very short compared to men, the bacteria can move up into the bladder and cause a bladder infection or urinary tract infections, Steiner said. But there are more risks for fungal, not bacterial infection.
"These clothing can cause chaffing and they can cause poor air circulation," Steiner said. "There's nothing yeast like better than a dark, wet place."
Steiner said women need not throw away all their thongs, skinny jeans and the like, just don't wear them all the time.
"The best thing women can do to reduce their risk is to eat a cup of non-fat yogurt with probiotic culture every day," Steiner said.
Can Stiletto Heels Hurt Your Back?
The price tag on those Manolo Blaniks might be even higher than most women think. As if the high cost of the high designer heels isn't daunting enough, doctors say these slender shoes can cause a chain reaction of foot and back problems.
"Wearing high heels regularly for long periods of time can lead to a contraction of the Achilles tendon," said Ronald Jensen, president of the American Podiatric Medical Association.
Though the extent of a tendon contraction varies, problems with the Achilles tendon can lead to serious walking problems and can be avoided by simply limiting the frequency of high-heel wear.
Jensen also notes that the constrictions high heels put on women's feet are dangerous from a stability standpoint. In particular, balance issues caused by high heels may lead to serious back problems.
High heels cause the wearer to unnaturally tip forward on the balls of their feet, ruining correct walking posture, according to Dr. Scott Boden, professor of orthopedic surgery and director of the Emory Spine Center at the Emory University School of Medicine in Atlanta.
Although he stresses that underlying conditions are ultimately the main determinate of whether back problems will arise, Boden says unusual posture caused by the shoes causes the lower back to rely heavily on the set joints, making the lower back especially susceptible to pain.
Are Flip-Flops Bad for Your Feet?
For many people, flip-flops seem like the perfect, comfortable, everyday solution for summer footwear. But these staples of summer style have more downsides than you may realize, as their flat soles and open-toe style allow for a number of potential podiatric issues.
Wearing any shoe without proper heel or arch support is potentially detrimental, according to both Jensen and Boden.
Jensen points to the lack of arch and ankle support found on cheaper (and, incidentally, more popular) flip-flops today, and Boden notes a potentially bigger medical issue, known as plantar fasciitis.
"Wearing shoes with little or no heel support can lead to plantar fasciitis, which is basically heel pain, and could require anti-inflammatory shots, or even possibly surgery," he said.
Cheap, flat sandals with little or no shock absorption potential can lead to other serious foot and ankle problems, such as severe tendinitis, that are not easily remedied.
In addition, flip-flops naturally provide no physical protection for the foot from falling or sharp objects. The American Podiatric Medical Association details the dos and don'ts of flip-flop wearing in its recent "Tips to Avoid a Flip-Flop Fiasco" bulletin, stressing the appropriate use and sizing if a person must wear sandals.
"It's OK to wear flip-flops in a poolside setting," Jensen said. "But they shouldn't be worn for yard work or operation heavy machinery."
But Jensen and the association's summer bulletin do both note that a well-structured flip-flop with an appropriate heel is fine to wear under the right circumstances.
Can Those Comfy UGG-Style Boots Really Hurt?
UGG-style boots may be all the rage in places like snowy New England, but their furry exterior is only a mask for potential foot and back problems. In a similar fashion to flip-flops, the flat soles of this popular footwear can cause arch, ankle and back problems.
Although boots have been attributed to causing plantar fasciitis as well, they also allow for other problems such as ankle tendinitis.
According the Jensen, a soft sole, as is often seen in furrier versions of the popular shoe, allows for a lack of foot support that the shoe should be giving. If a foot can slide around significantly, it will cause the tendons on the side of the ankle to stretch uncomfortably in order to maintain balance.
"Wearing the wrong shoes is no guarantee of back pain," said Boden, who added that many people can wear either heeled or flat shoes without resulting back problems.
But underlying conditions such as arthritis can potentially give way to physical pain and further back problems, brought on by the inappropriate support provided by some footwear.
Can the Wrong Bra Hurt Your Back?
It's popular -- especially among bra makers -- to report that the wrong bra can cause back and shoulder pain, but doctors say more blame lies with genetics and weak muscles than under wires or small straps.
"Bras are all about comfort and modesty; they don't have any physiological functions," Steiner said.
"Some women are perfectly happy to go without them and their breast are large, but they feel comfortable," said Steiner, who added other women with small breasts may not need a bra for support but feel more comfortable wearing them for modesty reasons.
Steiner's "number No. 1 bra myth" is that under wires cause cancer. Her number No. 2 myth is that the wrong bra can cause back pain.
"If you have an unsupportive bra, the bra won't cause back pain," Steiner said. "Having a properly fitted bra can alleviate a little bit, but back pain is related to large breasts, and insufficient back muscles and abdominal muscles."
Steiner recommends women suffering from back pain to strengthen their back and their abdominal muscles. Also, she recommends that women try on all bras before purchasing.
"Even if you have the same size breast as your next door neighbor, they may be a different shape," Steiner said.
Do Heavy Handbags Really Hurt Your Back?
At some point, whether it be the current fashion or a necessary diaper bag, many women end up carrying a heavy handbag during their lifetime.
But carry a heavy handbag too long, and doctors say you could risk back pain.
"Think about: Do you ever carry your handbag on the other side?" Steiner said. "You don't switch because it just feels weird."
Men aren't immune either; carry a laptop, briefcase or man purse for too long and men can develop muscle pain too.
"Because you have this heavy weight on one side, your muscles on the other side are straining to keep you upright," Steiner said.
One might ditch the overloaded bag for a smaller one and Steiner said it's also possible to avoid the problem if you can remember to switch sides daily.
But for most people who will continue to carry bags, and subconsciously put them on one side, Steiner has more realistic recommendations.
"Exercise to strengthen back muscles can help," Steiner said. "And the best way to carry your handbag is across around your neck and across your shoulder to the other side."