Can a bad, consistent cough damage my neck lift?

Its highly unlikely after 9 weeks that you have caused any damage, most of the initial healing is done so don't worry about damaging your results. 

Dear. Troylin,Thanks for your question. At 9 weeks post op, I think you'll be fine. However, I would definitely suggest that you see your doctor to address the cough. Hope you feel better soon.Kindly,Kouros Azar

So the soft tissues of the face heal pretty quickly. 9 weeks should be enough to have everything stuck down now unless you have a very heavy cough. I have heard of post op complications as late as three weeks to do with coughing but that the longest time.Hope that helps. Adam Goodwin

Thank you for your question.

It is highly unlikely that you would have caused damage to your neck area because of coughing 9 weeks after a neck lifting procedure.

I would recommend you see you GP to help treat the cough.

In general, a cough should not give you problems unless you cough so hard that you cause internal bleeding under the skin flaps.