You will also need to check with your insurance company. I was diagnosed with an arrhythmia and needed to obtain a letter from my doctor to say I was fit to travel otherwise they wouldn’t cover me.
Personally I wouldn't risk a long flight. If it is really important to you to go, then seek personalised advice from your doctor. It's your decision, so from that perspective you're allowed, but getting adequate medical insurance cover could be tricky and/or expensive.