A Singaporean man in his 70s died of deep vein thrombosis at the end of a seven-hour flight to Brisbane.

He was headed to the Australian city with his wife and son for a holiday. Upon landing at Brisbane airport, he stood up to retrieve their hand luggage from the overhead compartment, but collapsed suddenly.

Deep vein thrombosis happens when a blood clot forms in a vein deep in the body, such as in the lower leg. The clot can break off and travel through the bloodstream, obstructing blood flow if it ends up in an artery of the lungs. In some cases, it can be fatal.

Sitting for long periods of time can increase the risk of developing deep vein thrombosis - although chances of it happening while flying are relatively low.

Nee Soon GRC MP Lee Bee Wah, who represents the area where the man lived, said in a Facebook post on Oct 23 that she had attended his wake.

The man's wife told Ms Lee he was very fit and exercised regularly.

In her post, Ms Lee also shared some travel tips and reminded people who travel by air to get up and walk around the plane to improve blood flow in their calves.

"My main purpose of sharing this on Facebook was so people would know what to look out for when they travel," she told The Straits Times yesterday.

"Because a lot of Singaporeans travel frequently nowadays, they need to take precautions even when they're in an airplane."

NUR ASYIQIN MOHAMAD SALLEH