The phrase "challenge areas" refers to specific aspects or parts of something that are difficult or problematic. It indicates areas that require extra effort or attention to overcome obstacles or issues. Full definition
Employment law is one of the most challenging areas of law for any sized legal department. (tdslaw.com)
This means that school systems have access to funds needed to promote teacher growth, especially in challenging areas such as the tug of war between emotional health and rigorous learning. (educationpost.org)
The belly fat accumulated there is by far the most challenging areas for many people. (bodybuildingforyou.com)