Rob Stein

For the first time in decades, the number of children with asthma isn't increasing, federal scientists report. But cases continue to rise among African-American children and poor children.

For three decades, men who have sex with men were barred from ever donating blood. A new policy will allow gay and bisexual men to donate, but only if they've been celibate for at least a year.

Codeine can trigger rare, but life-threatening, breathing problems in kids. Food and Drug Administration advisers want to more tightly restrict the drug's use by anyone under 18.

When bodies decompose, the types of bacteria on and around the body change in predictable ways. These patterns can be used to estimate time of death, a crucial clue in solving murders.

Young doctors being trained at dozens of hospitals around the country are being asked to work up to 30 hours straight as part of a study. Critics say the study is risky and unethical.

The unusual meeting was called to consider a ban on certain uses of a new technique that can make precise changes in DNA. The main concern is altering genes in human sperm, eggs and embryos.

Hundreds of scientists from around the world are participating in a three-day summit in Washington, D.C., to discuss the promises and dangers of powerful new gene editing techniques.

One revision would crack down on studying tissue and blood samples without getting a person's consent. Another change would make it easier to conduct studies in many locations at once.

A decrease in PSA testing came after a controversial recommendation against routine screening. As a result, many fewer cases of the most common cancer to hit men are being diagnosed, research finds.

The National Institutes of Health has issued a moratorium on funding work that puts human stem cells into nonhuman embryos. The concern is that hybrids might develop human brain cells, sperm or eggs.

A genetic engineering technique raises hopes for eliminating diseases, such as malaria. But it is also sparking fears of unintended consequences if delicately balanced ecosystems are disrupted.

A rise in suicides plus an epidemic of overdoses from prescription painkillers and heroin are key factors that have undone a long-term improvement in death rates. A weak economy may have contributed.

A large study suggests some may use e-cigarettes to quit smoking tobacco. But the survey also shows that nearly 10 percent of young adults who have never smoked tobacco have used the devices.

For years, it's been saying women should get annual mammograms starting at age 40. Now it says they can start at 45 — and then cut back to every other year starting at age 54.

The American Cancer Society says new research supports changing the age at which most women should start getting yearly mammograms. But the group's latest advice still conflicts with other guidance.

More than 23,000 Americans end up in emergency rooms each year after taking dietary supplements, an analysis shows. Most cases are linked to weight-loss products or energy-boosting supplements.

Scientists have tried for years to grow artificial kidneys in the lab. They've gotten a bit closer by using stem cells to create an "organoid" much like a fetal kidney. But it's missing key parts.

One-third of women who froze ovarian tissue before undergoing cancer treatment and later had it transplanted back ended up having babies, according to a study of women in Denmark.

Scientists from the U.S., Japan and China won the 2015 Nobel Prize in Medicine. The 3 researchers won for discovering drugs used to treat parasitic diseases that affect millions of people each year.