David Cassidy Opens Up About Dementia Battle

Jillian Michaels: Polycystic Ovary Syndrome

The fitness guru and former The Biggest Loser coach has become somewhat of an ambassador for PCOS, a hormonal condition that affects the skin and menstrual cycle, after speaking out about it candidly. Because PCOS sufferers have a low chance of pregnancy, Jillian adopted a baby girl.

Lena Dunham: Endometriosis

The Girls star was diagnosed with endometriosis, a disease where uterus tissue grows outside the uterus, after years of chronic stomach pains. She had surgery in 2015 to treat the disorder.

"Two days after the surgery, I was better than I had been in ten years," she said. "The illness, nausea, heaviness, and fatigue were replaced by an alien absence of sensation."

Tom Hanks: Diabetes

In 2013, the actor revealed on _The Late Show _ that he had Type 2 diabetes.

Selena Gomez: Lupus

After being diagnosed with the autoimmune disease, which attacks cells, the pop star canceled her 2013 tour and took a hiatus to focus on treatment.

“I was diagnosed with lupus, and I’ve been through chemotherapy," she said. "That’s what my break was really about. I could’ve had a stroke."

Bret Michaels: Heart Disease

After suffering a mini stroke in 2010, the Poison frontman has had to undergo heart surgery. He's been in and out of hospitals since.

Charlie Sheen: HIV

In 2015, the actor announced on the Today show that he's HIV positive. Since then, several former sexual partners have sued Charlie, claiming the actor had put them at risk for an infection.

Elisabeth Hasselbeck: Celiac Disease

The talk show host revealed she struggled with the disease, which affects the digestive system, in her book, The G Free Diet. "No matter what I ate, I would soon be doubled over with cramps, awful indigestion, diarrhea — or all of the above simultaneously," she wrote in the book.

She now follows a gluten-free diet.

Lady Gaga: Lupus

In 2010, Gaga told Larry King she was diagnosed with "borderline lupus."

Venus Williams: Sjögren’s Syndrome

The tennis star had to withdraw from the US Open in 2011 after being diagnosed with the disorder, which is a disease that attacks the cells that produce saliva.

“The fatigue is hard to explain unless you have it,” Williams said. “Some mornings I feel really sick, like when you don’t get a lot of sleep or you have a flu or cold. I always have some level of tiredness. And the more I tried to push through it, the tougher it got.”

She still battles with the disease.

Halle Berry: Diabetes

The actress was diagnosed back in 1989 after she passed out and slipped into a coma during a taping of a TV show. "They told me I might lose my eyesight, or I could lose my legs," she said. "I was scared to death. I thought I was going to die."

Kim Kardashian: Psoriasis

After finding flakey, red patches on her legs in 2011, she went to a dermatologist who diagnosed her with the skin condition on an episode of Keeping Up With the Kardashians.

Missy Elliott: Graves’ Disease

After disappearing from the music world, the rapper reemerged in 2015 and blamed her absence on a rare thyroid disease. "It causes hair loss, your eyes bulge,” Elliott said. “My blood pressure was always up from just overworking.”

Thanks to medication, Missy has the condition under control.