WEDNESDAY, Jan. 26 (HealthDay News) -- As long as vaccinations against disease have been around, there have been die-hard opponents convinced that these shots do more harm than good.

(HealthDay News) -- Body piercings are increasingly popular, but they also come with potential health risks.

(HealthDay News) -- A stress fracture often occurs from a sudden increase in activity.

TUESDAY, Jan. 25 (HealthDay News) -- There's a worrisome uptick in the incidence of certain head and neck cancers among middle-aged and even younger Americans, and some experts link the trend to a rise in the popularity of oral sex over the past few decades.

WEDNESDAY, Jan. 26 (HealthDay News) -- The fact that NFL linemen can recover from back surgery and resume their playing careers proves that average people can be active after they have an operation for a herniated disc, say U.S. researchers.

WEDNESDAY, Jan. 26 (HealthDay News) -- Screening rates for the sexually transmitted disease chlamydia are significantly higher in the United States among young black and Hispanic women than among young white women, which might explain why black and Hispanic women have higher reported rates of the disease, a new study suggests.

WEDNESDAY, Jan. 26 (HealthDay News) -- Hispanic seniors in the United States are less likely than their white counterparts to be vaccinated against flu and pneumonia, a new study has found.

WEDNESDAY, Jan. 26 (HealthDay News) -- Orangutans have more diverse DNA than humans and it has remained relatively stable over 15 million years, say researchers who sequenced the genomes of six Sumatran and five Bornean orangutans.

WEDNESDAY, Jan. 26 (HealthDay News) -- Children are not born with a dread of snakes or spiders but learn these fears very quickly, a new study suggests.

TUESDAY, Jan. 25 (HealthDay News) -- Following a series of recalls of external defibrillators, a U.S. Food and Drug Administration panel of experts recommended Tuesday that the devices be held to stricter standards.

WEDNESDAY, Jan. 26 (HealthDay News) -- HIV-infected patients with liver cancer who are waiting for a liver transplant are more likely to drop off the transplant waiting list than other patients, a new study has found.

WEDNESDAY, Jan. 26 (HealthDay News) -- Scientists have pinpointed two gene variants that protect hepatitis C patients from anemia caused by antiviral treatment.

TUESDAY, Jan. 25 (HealthDay News)-- Prolonged exposure to loud traffic noise is strongly associated with stroke in people aged 65 and older, a new Danish study finds.

WEDNESDAY, Jan. 26 (HealthDay News) -- Arizona Congresswoman Gabrielle Giffords was moved to a rehabilitation center in Houston Wednesday morning after her doctors upgraded her condition to good from serious Tuesday night, another step in her remarkable recovery from a gunshot wound to the brain.

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

WEDNESDAY, Jan. 26 (HealthDay News) -- The odds of surviving cardiac arrest are greater if it is caused by a "shockable" arrhythmia and if bystanders can give CPR and a shock from a nearby automated external defibrillator (AED), a new study finds.

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

WEDNESDAY, Jan. 26 (HealthDay News) -- Diabetes now affects nearly 26 million Americans of all ages and 79 million people have what doctors call "prediabetes," according to 2011 estimates released Wednesday by the U.S. Centers for Disease Control and Prevention.

WEDNESDAY, Jan. 26 (HealthDay News) -- Replacing the commonly used blood-thinner heparin with a clot-dissolving stroke drug in dialysis catheters once a week may reduce the incidence of catheter malfunctions and infections, according to new research.

WEDNESDAY, Jan. 26 (HealthDay News) -- Five to 40 percent or more of births in the United States are induced early without any good medical reason, according to a new hospital-by-hospital report.

WEDNESDAY, Jan. 26 (HealthDay News) -- Women who undergo an abortion don't seem to face a greatly increased risk of mental health problems after having the procedure, a new study suggests.

WEDNESDAY, Jan. 26 (HealthDay News) -- The U.S. Food and Drug Administration said on Wednesday that breast implants may be linked to a heightened risk for a rare cancer, as evidenced in a small but growing number of cases that have been reported in recent years.