NEW YORK (Reuters) - U.S. stocks fell on Friday after a sloppy debut by Facebook Inc spoiled hopes that a spectacular open for the most-anticipated stock sale in years would brighten the mood in what has been a gloomy month for equity markets. Shares of Facebook, the social networking giant, were volatile in the busiest day ever for a trading debut. After early gains of more than 10 percent, Facebook shares fell back to the $38 issue price, ending up just 0.6 percent at $38.23. It was the Nasdaq's most actively traded stock, with more than 566 million shares traded. ...

FRIDAY, May 18 (HealthDay News) -- If you've been to the dentist with your children recently, you may have noticed that things have changed since you were a kid.

FRIDAY, May 18 (HealthDay News) -- Inflammation caused by chronic heartburn may increase the risk of esophageal cancer, a new study finds.

Here are some of the latest health and medical news developments, compiled by the editors of HealthDay:

FRIDAY, May 18 (HealthDay News) -- Despite being tested by long hours and frequent relocations and separations, military marriages are no more likely to end in divorce than civilian marriages, a new study shows.

FRIDAY, May 18 (HealthDay News) -- Stephanie Crowe, a mother of three from Croton-on-Hudson, N.Y., still remembers dreading a visit to the dentist as a young girl. It was often a painful experience, and her family's dentist showed little empathy to his smallest patients.

FRIDAY, May 18 (HealthDay News) -- Women who eat a lot of "bad" saturated fat may hurt their overall brain function and memory over time, Harvard University researchers report.

FRIDAY, May 18 (HealthDay News) -- Eating a healthy, calorie-controlled diet during pregnancy can help prevent excessive weight gain and cut the risk of obstetric complications, researchers report.

(HealthDay News) -- Reusable grocery totes may be friendly for the environment, but they can also befriend harmful bacteria.

(HealthDay News) -- Tracking your migraines can better prepare you to prevent or treat these often-debilitating headaches.

THURSDAY, May 17 (HealthDay News) -- Many people know diabetes -- both type 1 and type 2 -- can take a serious toll on physical health. But these blood-sugar disorders also can affect your emotions and, in turn, your emotions can wreak havoc on your diabetes control.

FRIDAY, May 18 (HealthDay News) -- Schools that charge kids to participate in sports may be benching some children, a new survey finds.

FRIDAY, May 18 (HealthDay News) -- Female athletes take longer to recover from concussions, a new study says.

FRIDAY, May 18 (HealthDay News) -- Older men have an increased risk of developing melanoma, but most are careless about sun protection and do not know how to properly check themselves for signs of skin cancer, a new survey reveals.

FRIDAY, May 18 (HealthDay News) -- One-third of homeless people in the United States are obese, about the same rate as the general population, a new study finds.

FRIDAY, May 18 (HealthDay News) -- A new test that can detect and predict osteoarthritis before patients experience symptoms was developed by analyzing the joints of dogs with arthritis.

FRIDAY, May 18 (HealthDay News) -- The U.S. Centers for Disease Control and Prevention wants all Americans born between 1945 and 1965 -- the baby boom generation -- tested for hepatitis C.

FRIDAY, May 18 (HealthDay News) -- Personal genetic testing does not lead to an increased use of health services, a new study finds.

FRIDAY, May 18 (HealthDay News) -- Young people can easily buy alcohol on the Internet, where they're also exposed to a wide range of advertising and marketing efforts from the alcohol industry, two new journal articles warn.

ABC News created a special version of our misophonia story that is stripped of some of the sounds that commonly trigger reactions from those who suffer from the condition. Watch parts 1 and 2 of the piece below.