Hands up if you've ever looked in the mirror and seen something you'd like to change?
While it's completely normal to experience a few self-doubts from time to time, for a small but significant number of people it's part of a debilitating and often hidden condition known as body dysmorphic disorder or BDD.
"Body dysmorphia is a mental disorder where people [are] really concerned about an imagined defect in their appearance," explains Dr Ben Buchanan, a clinical psychologist from Foundation Psychology who specialises in BDD.
"It might be their nose, their skin, their hair, whether they're tall enough or whether they're muscular enough.
"As a result of feeling this way, they often engage in avoidant behaviours like staying at home all day or compensatory behaviours like obsessively putting on make-up, doing their hair or trying to cover their perceived defects," he adds.
"And it's really, really debilitating for people."
While most people are aware of body dysmorphia, what's most surprising is how common it is.
The condition affects as many as two per cent of Aussies, but Ben stresses experiencing the odd insecurity about your appearance is not the same as having BDD.
"It's really normal to want to change aspects of your appearance," he explains.
"But if you start to think thoughts like, 'I cannot lead a happy life because of this one aspect,' that's when you know it's a real problem. Most of us might say, 'I wish my nose was a bit straighter but I know my life will still be fine.'
"But if you're saying, 'There's no way I can lead a happy life with my nose how it is,' then that's a problem."
Unlike eating disorders, body dysmorphia affects men and women equally.
It often surfaces at around age 16 or during adolescence. There's a genetic component, but it can arise from bullying or feeling family pressure to look a certain way, too.
"It causes a great deal of disruption in work or social life," Ben says.
"Lots of people with the disorder also can't get a job because they spend all their time in the mirror checking their appearance."
It can hurt relationships, too.
"Things happen like reassurance seeking where you'll constantly be asking your partner, 'Does my bum look big in this?' Or, 'Does my face look OK?' And that can be a big problem," Ben explains.
While body dysmorphia isn't new, social media has raised new issues.
Ben says when a patient is spending too much time on Instagram, he'll often set a lock to restrict their time on the app.
Plastic surgery can also raise its own problems.
"Most people who get plastic surgery are happier after," he tells.
"However, [of those] with body dysmorphic disorder, 83 per cent of people who get cosmetic surgery will be more distressed and dissatisfied after their surgery."
If left untreated, BDD can last for decades.
"Some people are lucky enough to grow out of it. But I've seen people in their 60s who have had it their entire life, and it's not until they get psychological treatment that they start to make headway," Ben shares.
For people seeking help, Ben says it's vitally important to find a psychologist who specialises in BDD.
"Because it's an under-recognised disorder, most GPs will never have heard of it and also most psychologists won't be skilled in treating it," he explains.
But there's also good news.
"Research shows that the majority of people who get good quality psychological therapy will benefit and some people can be completely cured," Ben says.
If you or someone you know needs help, contact lifeline on 13 11 14 or lifeline.org.au.