Lil Wayne -- Doctor's Orders ... NO FLYING

Lil Wayne is under STRICT ORDERS from his doctor to keep his ass off airplanes for the foreseeable future ... after his mid-flight medical emergency last week, TMZ has learned.

We broke the story ... Weezy was hospitalized Friday following two seizure-like episodes on board back-to-back flights.

He's been recovering since at his mama's house -- but sources close to the rapper tell us, Weezy's doctor has ordered him to rest for the next week at least ... which means no working, and definitely no flying.

We're told Wayne's been to the doctor twice since his hospitalization and has nurses coming to check on him regularly.

The rapper's telling friends he feels the seizures were a result of working himself too hard after his jail stint -- and has been calling the health scare a "life-changing event" and an "eye-opener."