THURSDAY, Sept. 9 (HealthDay News) -- Most teenagers think they're invincible, and that goes double for talented teenage athletes. They're young, immortal, at the top of their game, the envy of their friends.

THURSDAY, Sept. 9 (HealthDay News) -- Americans who have health insurance through large, employer-sponsored health plans will see a number of plan design changes in 2011, and they'll be paying more for that coverage, employers and benefits consultants say.

(HealthDay News) -- Acne, the most common skin disease, is not a dangerous condition. But it can lead to permanent scarring.

(HealthDay News) -- Low back pain, ranging from mild to severe, affects almost everyone at some point.

THURSDAY, Sept. 9 (HealthDay News) -- Obesity caused by heavy drinking can add to brain damage caused by drinking itself, says a new study.

THURSDAY, Sept. 9 (HealthDay News) -- Different risk factors contribute to indoor and outdoor falls among the elderly and these differences need to be incorporated into fall prevention programs, a new study suggests.

THURSDAY, Sept. 9 (HealthDay News) -- Mexican-American stroke survivors with a heart rhythm disorder called atrial fibrillation are more than twice as likely to suffer a second stroke compared to white patients, a new study finds.

THURSDAY, Sept. 9 (HealthDay News) -- About one in 10 athletes who competed at the 2010 Winter Olympics suffered an injury and about one in 14 became ill, according to a new study.

THURSDAY, Sept. 9 (HealthDay News) -- Here's yet another reason to avoid obesity throughout your life: Doing so may improve your chances of survival if you're diagnosed with colon cancer.

THURSDAY, Sept. 9 (HealthDay News) -- Obese women who have weight loss surgery before they get pregnant are three times less likely to develop gestational diabetes and are also less likely to require a cesarean section, a new study finds.

THURSDAY, Sept. 9 (HealthDay News) -- People who live in poor neighborhoods experience far more injuries than those in more wealthy areas, a new study has found.

THURSDAY, Sept. 9 (HealthDay News) -- Two new studies provide evidence that smoking can harm sperm - both in smoking men who may become fathers, and in sons born to women who smoked during pregnancy.

THURSDAY, Sept. 9 (HealthDay News) -- A newly developed assessment tool may give doctors and parents a heads-up about the kinds of medical problems that may face premature infants, researchers say.

THURSDAY, Sept. 9 (HealthDay News) -- A new study suggests that a quick MRI scan could tell doctors if a child's brain is maturing properly, potentially providing an early warning sign that mental problems are developing.

THURSDAY, Sept. 9 (HealthDay News) -- The number of people aged 50 and older admitted for substance abuse treatment in the United States has more than doubled since the early 1990s, says a federal government study released Thursday.

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

(HealthDay News) -- Here are the latest clinical trials, courtesy of ClinicalConnection.com:

THURSDAY, Sept. 9 (HealthDay News) -- In 2000, the U.S. government set modest goals for the amount of fruit and vegetables people should eat, but a decade later the majority of Americans are not even close to reaching those thresholds, health officials said Thursday.

THURSDAY, Sept. 9 (HealthDay News) -- The U.S. Food and Drug Administration cracked down Thursday on five distributors of electronic cigarettes, citing them for a series of violations that included unsubstantiated claims and poor manufacturing practices.