At 20, Tammi Kirkness was the walking, talking, hustling personification of success. She was kicking goals in the corporate world, had completed a psychology degree and was fit and healthy.
From the outside, her life appeared to be on a steep upward trajectory but inside, her incessant anxiety and need to achieve was edging her towards a breakdown.
"I was at my desk one day and out of nowhere I clutched my chest and thought I was having a heart attack," she says. "I jumped in a taxi to the emergency department and after being hooked up to heart monitors, doctors told me I was having a panic attack."
Tammi was shocked to find out she was experiencing "high-functioning anxiety". While not an official medical diagnosis, high-functioning anxiety describes a manifestation of anxiety that sees individuals inwardly experiencing constant worry, yet outwardly appearing calm and extremely capable.
"I was so surprised when the doctor said I'd had a panic attack because on the surface everything was going well — I'd landed a great job straight out of uni where I was well-respected, I had plans in place to travel to Europe, enough money to not need to work overseas, great friendships and I was fit and active," Tammi, now 31, explains.
According to beyondblue's lead clinical adviser Dr Grant Blashki, those experiencing high-functioning anxiety might appear in control, but, like Tammi, they're often struggling to keep all their figurative plates spinning.
"As a GP, the patients I see with high-functioning anxiety are quite exhausted both physically and mentally," Dr Blashki says. "Many are trying to keep an even keel and stay in control even though beneath the surface, there is a lot all negative self-talk, self-doubt and self-criticism."
Self-flagellation, perfectionism, over-thinking and exhaustion often go hand-in-hand with high-functioning anxiety and see those with the condition experience an overwhelming need to achieve more and more.
"I held my breath every time I'd open an email, had tense muscles, a clenched jaw, I was constantly over-analysing, couldn't fall asleep, had unreachable standards for myself and all of this contrasted with my articulate communication, the fact I was nicely dressed, was achieving well at work and was acting as though everything was fine," says Tammi.
As the most common mental health condition in the country, anxiety affects around one in four Australians. Women are at a higher risk of anxiety, with one in three females, and one in five men, experiencing it.
So how can you identify if you, or someone you love, has a problem?
"It's worth remembering that there is a spectrum of anxiety, and for many of us being anxious and worried about things is not a bad thing and creates great motivation for success and high-performance," Dr Blashki says.
"If that anxiety starts to dominate people's minds, and everyday activities become a battle against waves of social anxiety, obsessive worry or panic, that's when it becomes a problem."
After another terrifying panic attack at a Sydney train station that left her near paralysed with fear, Tammi finally sought the help she required.
Today, she relies on mindfulness, managing her perfectionism and disassociating her self-worth with her achievements to manage her condition day-to-day.
Now a qualified yoga teacher, corporate and life coach and the creator of Learn to Manage Your High-Functioning Anxiety, an e-course designed to help others, Tammi says "life is so flipping good".
"Most days are full of productivity without the fear and I have more fun than I ever did before," she says. "I also feel more connected to the real me and okay to be a walking contradiction of sometimes anxious and mostly calm.
"Outwardly I might not look that different to those around me; I still look healthy, on top of things and together — but the feeling is different. I used to feel like electric currents were running through me and now I feel grounded."
If you think you might be dealing with high-functioning anxiety, Dr Blashki has some pointers.
"The sorts of strategies that can help people with high-functioning anxiety include learning mindfulness skills, or seeing a psychologist for cognitive behavioural therapy," Dr Blashki says. "Visiting your GP is a good place to start."
• Lifeline: 0800 543 354 (available 24/7)
• Suicide Crisis Helpline: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• Youth services: (06) 3555 906
• Youthline: 0800 376 633
• Kidsline: 0800 543 754 (available 24/7)
• Whatsup: 0800 942 8787 (1pm to 11pm)
• The Word
• Depression helpline: 0800 111 757 (available 24/7)
• Rainbow Youth: (09) 376 4155
• CASPER Suicide Prevention
If it is an emergency and you feel like you or someone else is at risk, call 111.