Seven years ago, Jennifer Brea was working toward a Ph.D. in political science at Harvard University, looking ahead to a career in journalism or academia. After a trip to Kenya, she came down with a 104.7-degree fever. She recovered from the fever but kept falling ill. She had recurring infections, experienced dizzy spells and grew sensitive to sound and light. Increasingly, she wasn’t able to get out of bed. Sometimes she couldn’t even muster the energy to speak.

For more than a year, doctors weren’t able to give her a diagnosis. Some told her she was depressed, stressed out or dehydrated. One neurologist said that she had conversion disorder, a psychological condition in which a patient has neurological symptoms that can’t be explained by a medical condition—in her case, the doctor said, possibly caused by some distant, forgotten trauma.

Finally, a doctor diagnosed her with chronic fatigue syndrome, also known as myalgic encephalomyelitis—a little-understood disorder with symptoms including extreme exhaustion, an inability to get refreshing sleep and cognitive impairment. Now 35, Ms. Brea still struggles with the illness and has created a powerful account of her experience in a new film, “Unrest,” which has made the Oscar shortlist for best documentary.

She raised more than $210,000 through Kickstarter to make the film, in which she talks about her own illness and interviews other CFS patients over Skype from her bed. The documentary is streaming on PBS’s Independent Lens website through Jan. 22 and premieres on Netflix on Jan. 15.

Growing up in Orlando, Fla., Ms. Brea was an active, adventurous child. “I was playing outside from the moment I got home to pitch-black dark, then on the weekend my mom and I would go spend hours in bookstores” and at the movies, she says. Ms. Brea went to Princeton University, where she majored in politics, then enrolled at Harvard. She never completed her Ph.D.