A chronic illness is a long-term medical condition that requires treatment and management over a long period of time, usually years - sometimes a cure is never reached, only a control. Some of them are well known, like arthritis and diabetes, but there are many others who have received more attention in recent years because a celebrity has publicly disclosed the fact. Take Lady Gaga as an example, who revealed a few years ago that she has a condition called fibromyalgia.
While it is the responsibility of any individual to share what they want to share about their health, there is no denying that, especially in lesser-known conditions, having someone talk about it frankly and publicly can raise awareness, decrease stigma and be a force for action, as well as support for fans who may be struggling with something. Here we have listed some of the celebrities who have spoken publicly about their chronic health conditions.
Gigi Hadid: Hashimoto's Thyroiditis
This condition is also known as chronic lymphocytic thyroiditis and is a thyroid disease that can cause difficulty in concentration, hair loss, fatigue and weight gain. Gigi has said earlier that the illness really meant that she was struggling with not losing too much weight.
"My metabolism has really changed my mind this year," she said in 2016. "I have Hashimoto's disease. It's a thyroid disease, and it's been two years since the medication was taken."
Sarah Hyland: Renal Dysplasia
Renal dysplasia is a condition since birth in which the kidneys did not develop properly when the baby was in the womb. The Modern Family star said in 2015: "I was born with so many health problems that doctors told my mom that I would never have a normal life."
Hyland had a kidney transplant in 2012 at age 21, donated by her father. In 2017, she was furious at people who criticized her for losing weight on social media, saying it was because of her health problems.
Bella Hadid: Lyme Disease
Lyme disease is caused by a tick bite. When it is not detected early, it can cause long-lasting symptoms, such as joint pain, problems that affect the nervous system, extreme fatigue and heart problems.
In 2015, Bella's mother, Yolanda, who also has the disease, revealed that her daughter also has it. The model said it was so bad that she couldn't get out of bed for six days.
Singer Halsey is one of the many women who suffer from endometriosis. Speaking about it on Twitter a few years ago, she shared how she felt about the diagnosis: "Finding out that I had [endometriosis] was the most bittersweet moment, because it meant I wasn't crazy! I wasn't a 'baby!' I had every right to feel that the world was falling apart. But it was terrifying to find that out."
"Please know that you are not alone," she told her fans.
Selena Gomez: Lupus
In 2015, Gomez revealed that she had been diagnosed with lupus - an autoimmune condition that causes skin rashes, fatigue and joint pain - for which she underwent chemotherapy. The complications of lupus continued for Selena, with the need for a kidney transplant, which she received from her friend Francia Raisa.
Kim Kardashian: Psoriasis
Awareness was definitely raised about psoriasis when it was revealed that one of the most photographed women in the world had it. After initially going crazy about the skin condition - which causes red spots - in an old episode of her programme, she has since taken a more serene approach, saying she doesn't even try to cover it up any more.
"I'm always hoping for a cure, of course, but in the meantime, I'm learning to accept it as part of who I am," wrote Kim on her website.
Lady Gaga: Fibromyalgia
Fibromyalgia is a condition that causes pain throughout the body, and someone who suffers from it may also experience extreme tiredness, muscle stiffness, difficulty concentrating and trouble sleeping. The disease tends to affect women seven times more than men. There is no cure, but the symptoms can be relieved with medication, therapy and lifestyle changes.
Lady Gaga spoke about her experience with the disease for the first time in her 2017 Netflix documentary, Gaga: Five Foot Two. She was also forced to cancel a show in Brazil because she was taken to the hospital with severe pain.
Venus Williams: Sjogren's Syndrome
Despite being a tennis star, Venus Williams revealed that she had Sjogren's autoimmune syndrome in 2011. The condition affects parts of the body that produce fluids, such as tears and sweat, often leaving patients with dry eyes, dry mouth, tiredness and joint pain.
The condition forced the athlete to give up the sport in 2011, but soon she returned to the sport and became runner-up at Wimbledon.