Research shows that social media, with it endless promotion of unrealistic standards of beauty, has had a negative impact on millions of young people.

With the emergency phase of the COVID-19 pandemic in the rearview mirror, at least for now, we look back on a handful of stories that provided sharp insights at key moments in the pandemic.

The emergency status allowed the federal government to cut through a mountain of red tape, with the goal of responding to the pandemic more efficiently.

The method could enable a rapid test to determine whether individuals are producing antibodies that help protect against Covid-19.

During the pandemic, American Indian and Alaska Native populations experienced nearly six times the mortality of white people from alcohol-associated liver disease.

Mobility-related data show the pandemic has had a lasting effect, limiting the breadth of places people visit in cities.

As the government’s oldest consumer protection agency, the FDA has long butted up against drugmakers, activists and politicians. But undermining its work could be harmful to patient health and safety.

Pennsylvania has long had one of the highest death rates from drug overdose in the US. But new studies suggest counties throughout the state have different rates of opioid deaths.

Harvard epidemiologist looks back and ahead.

Avian influenza viruses have evolved to infect birds, but the current H5N1 outbreak is also infecting a wide range of mammals. This suggests that it could mutate into forms that threaten humans.