Trouble

No. People who have difficulty sleeping have much higher incomes than people who have trouble sleeping.

But seriousl

CalifJim it's just a matter of a difference of register between the two words, so my joking is not that far off from the truth.CJ

So there might be some people who have little difficulty but do have trouble sleeping; they can get to sleep but wake up in the middle of the night, right?

That's not at all what Jim said. The two problems you describe would not be differentiated by labellng one "difficulty" and the other "trouble." Rather, they would be described as trouble/difficulty falling asleep and trouble/difficulty staying asleep.
"Trouble" is more conversational; "'difficulty" is more "formal" or "official." A doctor would probably say "difficulty."

khoffThe two problems you describe would not be differentiated by ...
...
A doctor would probably say "difficulty."

Precisely.

CJ

khoff."Trouble" is more conversational; "'difficulty" is more "formal" or "official." A doctor would probably say "difficulty."

AH! Now I understand Jim's joke. When I first read it, quite honestly, I had no idea what he was talking about. Thanks for the explanation.

So, it's just a matter of formality and there is not really a semantical difference b

TakaSo, it's just a matter of formality and there is not really a semantical difference between 'trouble sleeping' and 'difficulty sleeping', right?

Exactly.

CJ

OK.

Thank you both!