Walker White never kept a diary, but when his wife, Lindsay, was diagnosed with lymphoma in April, he started a Web log.
What began as a message center about tests, spinal taps and diagnoses evolved into a kind of personal journal, he said. "It became pretty clear to me it was an outlet for me," said White, 39, who lives and works in Washington. "I think it made me think through the issue and it made me think about what lay behind us and what lay ahead of us."
The Internet is now teeming with some 15 million blogs. Although the medium first drew mainstream attention with commentary on high-profile events such as the presidential election, many now use it to chronicle intensely personal experiences, venting confessions in front of millions of strangers who can write back.
Nearly half of bloggers consider it a form of therapy, according to a recent survey sponsored by America Online Inc. And although some psychologists question the use of the Internet for therapy, one hospital in High Point, N.C., started devoting space to patients' blogs on its Web site, a practice Inova Fairfax Hospital is also considering.
The patients use only first names on their blogs. Mary, a patient at the High Point Regional Health System, started blogging about ups and downs following her mini-gastric bypass surgery in March.
"Before having this surgery, I could look at the largest person on earth and think I was as big or bigger," she wrote.
The project has been so successful -- both as a marketing tool for the hospital and a form of group therapy for patients who get feedback from their readers -- that High Point is considering adding video blogs, said Eric Fletcher, a spokesman for the hospital.
Most individual bloggers use Internet sites like Google, Yahoo, Lycos, MSN and AOL, which offer free software for users to set up their blog and add or withdraw comments. Blogs are different from the personal Web pages that were popular a few years ago because they are more interactive, designed to look like a dialogue between the blogger and the audience.
Although AOL provides tools that allow bloggers to limit their audience to selected viewers, most don't, said Bill Schreiner, vice president for AOL's community programming. "It's like they're writing the novel of their lives, and [public] participation adds truth to their story."
Blogging combines two recommended techniques for people to work through problems: writing in a journal and using a computer to type out thoughts. Some bloggers say the extra dimension of posting thoughts on the Web enables them to broach difficult subjects with loved ones, as well as reap support from a virtual community of people they don't know.
"I think it's a way of validating feelings. It's a way of purging things inside of you," said Judith HeartSong, a 41-year-old Rockville artist. As a child, she kept diaries filled with anguished accounts of abuse hidden under her bed, she said, but now she posts entries on the Web.
"This month is the third anniversary of my sobriety . . . three years totally free of alcohol," HeartSong wrote in a recent Web log entry. "Next month is the third-year anniversary of my leaving my old life."
Although it may feel good to blog, psychologists warn that going public with private musings may have ramifications, and that little research has been done on the consequences of the Internet confessional.
"I certainly don't advise anyone to do it. They're taking a big risk," said Patricia Wallace, a psychologist and researcher at Johns Hopkins University and author of "The Psychology of the Internet." People open themselves up to cruel comments, and worse: identity theft, for instance, or even losing a job for kvetching about a boss.
HeartSong said most of her reader comments are positive, but that she does get occasional attacks. At one point, she received so many hostile and threatening e-mails from a reader that she asked AOL to intervene and prevent the man from contacting her again, she said.
Some bloggers are unprepared for the attention and don't realize that what seems to be a disposable medium is anything but.
"It seems that although we tell people that the Internet is a public space, people just don't get it," said Susan B. Barnes, associate director of the Lab for Social Computing at the Rochester Institute for Technology, which studies social issues in computing. A blogger can erase a previous entry, but it's often saved on an Internet server and remains visible for years to come. "If you have a journal, that's your private journal, and it's assumed that you can control your journal. But what if it's online?"
White initially felt cloaked from public view by the vastness of the Internet, assuming that few people would be interested in his inner thoughts. But he was wrong: "You find out pretty quickly that a lot of people you don't expect to read it, read it."
Despite the element of risk, the relationships that develop between the writer and the audience can become very real, said Matthew G. Kirschenbaum, assistant professor of English at the University of Maryland, who studies blogs.
Pamela Hilger, for example, considers herself a member of a very tightknit community of dozens of people who read each others' online journals -- even though, after more than two years, most know her only by her first name.
"My father used to say, 'You don't air your dirty laundry in public,' " she said. But now Hilger, who lives in Los Gatos, Calif., said she shares nearly everything online, including photos of scars from the surgery she had after her lung cancer was diagnosed in June. "After I was diagnosed, the first people I turned to are my friends and journaling buddies," said Hilger, who reads about 50 other blogs. "They're never failing with support and encouragement."
Her readers send e-mails if she doesn't post daily messages. Some want to start an online fund to help pay her medical bills. When her fellow blogger's brother split from his wife, several online friends drove hundreds of miles to save the man's dogs from the pound where the wife had left them.
"With my blog, I've learned how to share things with people that are close to me," including her sister and her 14-year-old daughter and 20-year-old son, she said. But of the 6,271 comments she has received over the years, most are from complete strangers who found her online. "Sometimes it's easier to write about it to 1,000 strangers than to sit face to face with someone you know well."