Facebook Inc. already knows who your friends are and the kind of things that grab your attention. Soon, it could also know the state of your health.

On the heels of fellow Silicon Valley technology companies Apple Inc and Google Inc, Facebook is plotting its first steps into the fertile field of healthcare, said three people familiar with the matter. The people requested anonymity as the plans are still in development.

The company is exploring creating online “support communities” that would connect Facebook users suffering from various ailments. A small team is also considering new “preventative care” applications that would help people improve their lifestyles.

In recent months, the sources said, the social networking giant has been holding meetings with medical industry experts and entrepreneurs, and is setting up a research and development unit to test new health apps. Facebook is still in the idea-gathering stage, the people said.

Healthcare has historically been an area of interest for Facebook, but it has taken a backseat to more pressing products.

Recently, Facebook executives have come to realise that healthcare might work as a tool to increase engagement with the site.

One catalyst: the unexpected success of Facebook’s “organ-donor status initiative,” introduced in 2012. The day that Facebook altered profile pages to allow members to specify their organ donor-status, 13,054 people registered to be organ donors online in the US, a 21-fold increase over the daily average of 616 registrations, according to a June 2013 study published in the American Journal of Transplantation.

Separately, Facebook product teams noticed that people with chronic ailments such as diabetes would search the social networking site for advice, said one former Facebook insider.

In addition, the proliferation of patient networks such as PatientsLikeMe demonstrate that people are increasingly comfortable sharing symptoms and treatment experiences online.