Nurses who wear long artificial fingernails can also cause serious problems. These glue-on nails can rip through disposable gloves. Even more dangerous, they're often breeding grounds for bacteria and yeast. A recent study from Michigan found that nearly three-quarters of nurses who wear such fingernails carry a staph infection underneath them. Even careful handwashing doesn't effectively kill all of the germs.
Most hospitals establish their own dress and grooming codes for care providers.