7 major health lessons we learned from celebrities in 2015

"Unbroken" director Angelina Jolie arrives at the 20th Annual Critics' Choice Movie Awards in Los Angeles, California January 15, 2015. (Reuters)

Like it or not, celebrities are a major force in American culture. That can be a bad thing when famous people spread misinformation (just because you’re known, doesn’t mean you’re in the know), but it can be a truly great things when celebs use their platform for good. In 2015, there were a handful of celebrities who did just that by sharing their own health struggles. In turn, they raised awareness about diseases affecting people around the world. Here, seven people who opened our eyes this year, and what we learned from them.

Angelina Jolie
All the way back in March, Angelina Jolie Pitt wrote a touching New York Times op-ed about her decision to have preventive surgery to remove her ovaries and fallopian tubes, just two years after having a preventive double mastectomy. Jolie Pitt carries a mutation in the BRCA1 gene that gives her an 87 percent chance of developing breast cancer and a 50 percent chance of developing ovarian cancer. Her first preventive surgery dramatically reduced her risk of developing breast cancer, and the latest surgery will likely keep her safe ovarian cancer.

Related: 12 Things That Actually Don’t Increase Your Risk for Breast Cancer

What made her story truly inspiring was that a cancer scare was what prompted the surgery, and she was able to speak so movingly about a feeling so many people have experienced: “I went through what I imagine thousands of other women have felt. I told myself to stay calm, to be strong, and that I had no reason to think I wouldn’t live to see my children grow up and to meet my grandchildren,” she wrote. She was also adamant about the need for other women with BRCA mutations to educate themselves about the many options available to find the one that’s right for them.

Selena Gomez

In an October interview with Billboard, Selena Gomez answered rumors that she was treated for addiction during a 2013 hiatus, revealing that in fact, she took some time off to be treated for lupus, a chronic autoimmune disease.

Gomez’ admission raised the profile of the potentially life-threatening disease that is often hard to diagnose, and started conversations about what it’s like to be seriously sick without looking like it. “I was diagnosed with lupus, and I’ve been through chemotherapy. That’s what my break was really about. I could’ve had a stroke,” Gomez told Billboard. “I wanted so badly to say, ‘You guys have no idea. I’m in chemotherapy. You’re a–holes.’ I locked myself away until I was confident and comfortable again.”

Lesson: never assume you know what others are going through.

Related: 9 Celebrities With Lupus

Jimmy Carter

In August, former President Jimmy Carter announced that he was being treated for melanoma that had spread to his brain. The sad news (followed by an awesome recovery) brought attention to a new form of treatment for the disease–pembrolizumab (Keytruda). The drug is part of a rapidly growing class of drugs called immunotherapy, which uses the body’s immune system to fight cancer. Keytruda received accelerated approval by the U.S. Food and Drug Administration (FDA) for advanced melanoma in 2014, and this year the agency granted the drug the same for treating certain lung cancers.

This month, President Carter announced that he is now in remission.

Avril Lavigne
After ominously hinting at her health issues in a series of vague Twitter posts, Avril Lavigne opened up to People about her experience with Lyme disease. “I could barely eat, and when we went to the pool [at my 30th birthday party], I had to leave and go lie in bed,” she explained in an April interview with the magazine. “My friends asked, ‘What’s wrong?’ I didn’t know.”  After months, she finally got a diagnosis; her suffering was likely the result of the tick-related infection. By speaking out about her condition, Lavigne not only spread knowledge about the disease itself, but also about the importance of taking anti-tick precautions like bug spray and staying in the center of hiking trails.

Chrissy Teigen and Tyra Banks

After getting bombarded with questions about having kids over the years, Chrissy Teigen got real about her struggle with infertility on an episode of FABlife. She later told E! News, “usually I’m getting crap from people [on social media], but the amount of stories that were shared was really cool to see.” Since discussing her struggle, Teigen announced that she and husband John Legend are expecting a child.

Related: 15 Factors That Affect a Woman’s Fertility

Charlie Sheen

In November, Charlie Sheen announced in an interview with Matt Lauer that he is infected with HIV, the virus that causes AIDS. Sheen told Lauer on-camera that he decided to announce his status to end an extortion campaign that cost him millions of dollars, adding “I have a responsibility now to better myself and to help a lot of other people, and hopefully with what I’m doing today, others may come forwards and say, ‘Thanks, thanks, Charlie.‘” The day of the interview social media exploded, with many commending him for making a public declaration about a disease that still carries an unfortunate stigma.

Hayden Panettiere
Hayden Panettiere has no shame about her struggle with postpartum depression, and she’s been outspoken about how it shouldn’t be swept under the rug. During an interview on Live! With Kelly and Michael in September she touched on the shame associated with the disease. She also explained that it’s more than just “baby blues.”

“It’s something I think needs to be talked about, and women need to know they’re not alone, and that it does heal,” Panettiere said.

In October, she checked into a rehab facility to get help for the disorder.

This article originally appeared on Health.com.