He was admitted to a Sydney hospital on January 23 with a swollen calf, where the blood clot was diagnosed.
Lehmann was forced to miss Australia's Twenty20 series against India and the one-day international tour of New Zealand before being given the all-clear to join the ongoing Test series against the Black Caps.
He said the scare was a wake-up call, with the 46-year-old still on medication and forced to wear a compression stocking each day.
"I think a shelf life if you have success is four to six years," he told the Sydney Morning Herald, of a role that requires him to be away from home for 300 days a year.
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John Buchanan did the job for eight years between 1999-2007, but Lehmann said it was different now.
"I don't think you could do that now; the job's gotten bigger and bigger," he said.
"If I got to 2019 that'd be six years. I couldn't see myself going past that at all. I think my wife would kill me if I went past that."
The blood clot has seen Lehmann re-think his diet and lifestyle.
"It's like everything you get with those difficult situations, you get a reality check," he said.
"You take stock of where you want to get to and what you want to do and all those sorts of things.
"Just trying to work through those issues with diet and the regime of travelling day in, day out. But I feel good, it's just one of those things that happens.