Fans of ailing martial arts superstar Jet Li Lianjie have been sharing their own personal battles with hyperthyroidism, the illness the 55-year-old actor is suffering from, as news of his frail appearance continues to make shock waves.

Li, the Hollywood icon who starred in Lethal Weapon 4, Romeo Must Die, Kiss of the Dragon and more recently Expendables 2, is suffering from hyperthyroidism as well as spinal problems.

Li has said that his resting heart rate can go up to 130 beats per minute because of his illness, and that he cannot do any rigorous exercise.

While Chinese netizens prayed for his health on Saturday, news of his condition has spread across the English-speaking world with fans across Hong Kong, Singapore, Malaysia and the US expressing disbelief that they were seeing the same Beijing-born actor, who has appeared in dozens of action movies spanning four decades.

Is this the same Jet Li we all know? Martial arts legend battles illness and injuries as fans express shock.

Others mentioned their favourite Jet Li films, while some fans posted their own personal battles with the condition in the comments section as they tried to help raise awareness of hyperthyroidism.

Li says his strong belief in Buddhism as well as meditation and scripture reading help stabilise his condition.