When she was diagnosed with breast cancer in May 2015, Christa Wittmier wanted to withdraw from life.

A Honolulu entertainment blogger and well-known DJ on the club circuit, Wittmier didn’t want to tell anyone about the advanced stage of her cancer, as the dire turn of events felt intensely personal. But somehow Wittmier found the courage to blog about it a few weeks later.

It felt like a huge, emotional release, she said.

“It wasn’t until I felt I had hit rock bottom and realized I couldn’t do this alone,” said Wittmier, 40. “I think putting it out there, for me, was the biggest hurdle — opening myself up to letting people help me.”

Wittmier had tapped into a growing trend. For many like her, fighting a serious illness is no longer a private affair.

With their widespread availability, social media and other online platforms have provided people suffering from serious illnesses a way to share their experiences with a broad audience. A few have originated in Hawaii, including Wittmier’s blog and those by Honolulu teacher Kym Roley (ovariancancerfighter.com) and Mililani resident Jennifer Ozawa (mrshawaii.wordpress.com).

The benefits were huge, said Wittmier. Once she started, she felt relieved and was buoyed by the swell of online support from friends, acquaintances and even strangers.

She documented her experiences — from diagnosis to chemotherapy, hair loss and fevers, as well as her exploration of alternative therapies — on the Snapchat app and a blog, snapchatcancer.com. Through highs and lows, Wittmier exhibits her underlying sense of humor and continues to have a positive outlook.

“By and large I think it’s beneficial,” said Erin Bantum, an associate professor at the University of Hawaii Cancer Center who has researched the effectiveness of blogs and online support forums. “Going through cancer can be a real isolating experience if you don’t know many people who have it. One thing we know, social support is related to better adjustment. People, psychologically and physically, just do better when they have a social support network.”

Blogs generally serve two purposes, according to Bantum, who holds a doctorate in clinical health psychology. Some are problem-focused, intended to exchange medical information about options and treatments. Others are emotion-focused, designed to connect with others, offer moral support and document what a patient is going through.

Ozawa, a lifelong writer and mother of three, found her blog to be a form of therapy after her breast cancer diagnosis in March 2012. Her husband, Ryan Ozawa, set up a WordPress site called “Jen’s Cancer Blog: Information and Updates for Family & Friends” and encouraged her to write about her experiences.

She began posting entries about a week after her diagnosis, deciding to be completely candid about the experience — from mastectomy to chemotherapy and reconstructive surgery a year later. She shares tips but also talks about the anxiety she went through and relationships with her family.

Ozawa’s recent posts focused on the discovery in August of cancer in her bones, which she learned is treatable.

“I think when it comes to something like this, sharing is always good because cancer is very lonely,” said Ozawa, 44. “And anything that people can grab on to to help them feel less lonely is worthwhile. Every single person I know has been touched by (cancer) in some way, and I didn’t know until I started the blog. I really feel like I’m not alone now.”

What really made it worthwhile, said Ozawa, a cashier at City Mill in Mililani, is when a high school friend told her the blog helped her get an early diagnosis for breast cancer, which saved her life.

While going through the challenges of cancer, Ozawa wrote that it taught her the true meaning of love. Once realizing that life is short and fragile, she said, you learn not to sweat the small stuff and discover your priorities, which for her is family.

“I hope if my children, all of them, learn nothing else from this experience, it’s compassion,” she wrote in her most recent post.

Sharing was also beneficial for ovarian cancer survivor Roley of Aiea, who beat the odds and wanted to help others going through the same struggles. She was inspired by a blogger in Washington state, where she grew up.

Her first blog post was like “throwing up a little bit” and getting it all out, Roley said. Then she couldn’t stop.

“If I have an idea, I start and I write and write,” she said. “I realized that my information can be helpful to other people.”

After her first diagnosis of ovarian cancer in August 2012, Roley, now 53, underwent surgery to remove a cantaloupe-size tumor from her ovaries, followed by chemotherapy. She was clear a year after treatment, but the cancer resurfaced in one of her lymph nodes on a day she’ll never forget: Valentine’s Day 2014.

On her blog she has shared tips on what to expect while undergoing radiation, how she dealt with the side effects of vomiting and migraines, and the joy she felt when she survived to see her son, the youngest of her three children, graduate from high school in May.

One of her most recent posts celebrated what she calls her four year “cancer-versary,” or four years without any sign of cancer in her body.

“It’s been incredible to see how wonderful people can be,” she said. “I also wanted a record for the kids so they could see what their mom was thinking, feeling, saying and doing.”

Today the physics teacher at Mid-Pacific Institute wears teal on Tuesdays to raise awareness about ovarian cancer. And she remains positive, even with the knowledge the cancer could always come back.

One of the risks of opening your life up to a public forum, according to all three bloggers, is receiving unsolicited advice — even if well-intentioned — on treatments and what to eat and how to do live. They accept it as part of the blogging experience and said the benefits still outweigh the negatives.

Bantum, the University of Hawaii Cancer Center researcher, said blogging can be a useful tool for cancer survivors, but it’s not for everyone. Some might benefit more from an online discussion board moderated by a facilitator, while others might do better with the face-to-face interaction that’s possible only through a support group.

She cautions that everyone’s experience is going to be different.

“It’s good to go into it knowing everybody’s experience is unique, even with their diagnoses and treatment,” she said. “We should be going into it with as open a mind as we can.”

And there are parameters to consider when sharing online.

For instance, someone who is emotionally fragile might feel worse after reading about someone else’s bad experience or learning that an online acquaintance did not survive the illness, she said. Before starting, Bantum recommends thinking about what you want to get out of the blog.

“I think it takes knowing where we are at, emotionally,” she said. “If you’re frustrated or angry about something, just think thoroughly about it before you send it out.”

Wittmier, who is now recovering from surgery and whole brain radiation after the cancer recurred in her brain, liver and lungs, is now determined to share and help as many people as she can.

She offers a paper she wrote, “Cancer Plan of Attack,” a sort of guide to those newly diagnosed, with anyone who asks. Her “snaps” eventually became part of a video, “Snapchat Cancer Flow,” that aired at TedxHonolulu in July. She was initially planning to speak at the event before the cancer resurfaced.

Her goal is to finish a documentary film about her journey that she calls “Invisible Illness.”

Until then, Wittmier will stick to a simple philosophy she is eager to share with others through her blog and other outlets: Every day she wakes up at the break of dawn and takes nothing for granted.