Oprah Winfrey feared the "worst" after seeking an online diagnosis when she fell ill.
The 64-year-old media mogul turned to the Internet when the left side of her chin swelled up but was scared by the results she found when she searched for "swollen lymph gland causes".
She wrote in an essay for O, The Oprah Magazine: "None of the results were good. For the next four hours, I thought the worst. Why would a neck suddenly swell? Maybe it wasn't sudden. Maybe whatever it was had been growing for days, or longer, and I only now noticed."
Oprah immediately booked a doctor's appointment, where she expected to be told she had a "terrible disease" - so was stunned when she was given the real diagnosis and a simple solution to combat her symptoms.
She continued: "When I finally opened my mouth to say 'ahhh,' I was prepared for the doctor to say, 'I'm so sorry, Ms. Winfrey, you have. Insert terrible disease.'
"What she actually said was, 'I think your salivary glands are blocked. Go home, drink plenty of water, and try sucking on some lemons to stimulate your salivary ducts.' "
The 'Wrinkle in Time' star was so stunned by the doctor's verdict, she went for a second opinion - and received the same diagnosis.
She added: "I couldn't believe it. I'd worked myself up to a blood pressure reading of 150/80 thinking about how I was going to rearrange my life to deal with whatever this was. Drinking water and sucking on lemons couldn't be the answer.
"So I called another doctor. Sent photos of my bloated neck and said 'ahhh' over FaceTime.
"He confirmed: salivary gland blockage, inflammation. Drink lots of water. Suck on a lemon or a sour lemon candy."
After following advice, Oprah's symptoms quickly disappeared.
She said: "I downed a half gallon of lemon-flavoured water and sucked and puckered lemon slices through the night. By the next day, the swelling had gone down measurably. In two days, it had all but disappeared."