Singer-songwriter Carly Simon, 83, has revealed her diagnosis with Parkinson's disease and treatment for basal cell carcinoma. Simon, known for her 1972 hit "You're So Vain," has been largely out of the public eye for the past seven years.

In a statement to People, Simon described the progression of her symptoms, which initially included arthritis in her knees and hip, leading to three joint replacement surgeries. Despite these procedures, her mobility continued to decline, making it difficult to stand from low chairs and couches.

"Eventually, there were periods when I could not walk without considerable help," Simon wrote. "After an extensive evaluation at the Mayo Clinic, I was diagnosed with Parkinson’s."

Parkinson's disease is a progressive, incurable neurological condition that can cause muscle stiffness, slowness of movement, tremors, sleep disturbances, and chronic fatigue. Simon noted that the disease affects individuals differently and can be unpredictable, impacting not only physical movement but also potentially causing anxiety, depression, exhaustion, and apathy.

"It is not simply sadness or laziness," she explained regarding apathy. "It is as though the part of the brain that sends out invitations to participate in life has temporarily misplaced the guest list."

During the same period as her Parkinson's diagnosis, Simon also underwent treatment for basal cell carcinoma on her face. The surgery to remove the cancer altered her appearance, leaving her feeling more self-conscious about public appearances. She noted the irony of her hit song "You're So Vain" in light of her heightened self-awareness about her looks.

"Between my mobility issues, the Parkinson’s diagnosis, the surgery, and the emotional effects of it all, withdrawing from public view was the most palatable reaction," Simon stated.

Despite these health challenges, Simon has been working on new music, including her upcoming album, "Comes in Waves," which is her first in 18 years. She described the creative process as a source of structure and purpose.

"Working on the music gave shape to days that did not always have much shape," she said. "It gave me somewhere to go without having to leave the room. It reminded me that illness can change your life without becoming the whole of your life."

Simon expressed gratitude for the support of her children, family, friends, caregivers, and medical professionals. She shared her diagnosis to acknowledge the concern from those who have reached out.

"These days I move more slowly, I lean on others more than I once did, and I have learned to accept that every day will look a little different. But I am still very much here," Simon concluded.

Simon's last public appearance was in October 2019, and her last performance was in March 2018. She shares two children, Sally and Ben, with her ex-husband, musician James Taylor.