Condition That Causes Sleep Difficulties

This page is the CodyCross answer for the clue below from Under the sea, Group 35, Puzzle 3.

Question is: Condition That Causes Sleep Difficulties

and the answer is: INSOMNIA

Word Meaning:

INSOMNIA — (medicine) A sleeping disorder that is known for its symptoms of unrest and the inability to sleep.

Definitions from Wiktionary.