Ashley Tisdale suffers from alopecia.
The 'High School Musical' actress has found over the years that her hair starts falling out when the autoimmune condition flares up during times of stress, most recently when moving house and starting a new job.
She wrote on Instagram: "Alopecia and hair loss are fairly common, but a lot of people feel embarrassed to talk about these issues. Any type of hair loss can affect your self-esteem, especially if you feel like you’re the only one going through it. That’s why I want to talk about it openly—because it’s nothing to be ashamed of.
"Sometimes it’s connected to hormones, other times to heredity, and for me, it’s connected to stress overload. Today on @frenshe I’m sharing what I’ve learned about my alopecia and how I help manage it."
On the website for her Frenshe skincare website, the 37-year-old star - who has 21-month-old daughter Jupiter with husband Christopher French - went into more detail about what had happened a few months ago.
She explained: "A couple of months ago, while simultaneously moving, starting a home renovation, and kicking off a TV project, I noticed that a patch of my hair was starting to fall out.
"Nothing major—just a small section behind my ear—but still, it was happening, and not for the first time. A few years ago, the same thing happened when I was overly stressed, so I knew exactly what I was experiencing: alopecia."
Ashley finds her hair eventually grows back and she tries to tackle it with yoga, meditation and therapy.
She said: "I find what has helped me, is stress management. Obviously, mediation.
"A lot of the time, my Cortisol is up, because I'm sometimes putting stress on myself for no reason, but it's really important to know what's a big deal versus what is not a big deal."
Ashley also tried platelet-rich plasma injections (PRP) - which uses a patient's own blood cells to accelerate healing in a specific area - and although "expensive", she's seen good results.
She said: "It is more of an expensive route. But, I do find it's really helpful for alopecia."
The 'Masked Dancer' judge has also found adopting an autoimmune paleo diet, which eliminates and then reintroduces certain foods to promote gut health, to be beneficial.
She said: "It first of all just makes you feel better. And it really is healing towards the gut. You don't want to kind of be on it for a lifestyle diet, but it's good to do a 30-day thing with it.
"It's basically like, paleo but you're cutting out grains and other foods that are allowed, like eggs.
"Obviously alopecia is an autoimmune disease, so I would say that would be something to look at and see if it's something you can follow and try it."