Film producer and director Alfred Cheung Kin-ting saw seven specialists and spent at least $20,000 on tests and scans, but no one diagnosed him as suffering from panic attacks.
At first, Mr Cheung thought he had Parkinson's disease after he noticed his right hand trembling while filming The Highbinders, a Jackie Chan movie, in Thailand.
Mr Cheung said: 'I woke up more than 10 times a night and found my right fingers trembling and my eyes red. I thought I had Parkinson's disease because the symptoms were similar to Michael J. Fox's.'
He went to the Internet and read about the Canadian actor, who retired from the hit television series Spin City because of the disease.
But Mr Cheung was eventually diagnosed with panic disorder when he went to Chinese University's Mood Disorders Centre.
It took fellow sufferer, radio DJ Tsang Chi-wah, even longer to identify his problem. Tsang, who had been afraid of driving through tunnels for 10 years, went to various specialists but was diagnosed with different conditions each time.