When combined, 障碍 (zhàng'ài) creates a powerful compound word. You have a “wall” (障) and a “stone” (碍) together, reinforcing the idea of a solid, significant, and formidable obstacle that stops you in your tracks.
The concept of an obstacle is universal, but 障碍 (zhàng'ài) carries a certain weight in Chinese that is worth noting. While English might use “challenge,” “hurdle,” or “obstacle” somewhat interchangeably, 障碍 is less about a challenge to be athletically cleared and more about a fundamental barrier that must be systematically dismantled or circumvented. A useful comparison is the Western idea of a “roadblock” versus a “hurdle.” A hurdle is part of the race; you are expected to jump it. A 障碍 is more like an unexpected and serious roadblock that wasn't part of the original plan. It forces you to stop, reassess, and find a new strategy. This is especially evident in its formal application to social and medical issues. Terms like 语言障碍 (yǔyán zhàng'ài) (language barrier) and 学习障碍 (xuéxí zhàng'ài) (learning disability) are standard, neutral terms in Chinese. They frame the issue not as a personal failing but as a specific, definable barrier that can be addressed with specific strategies. This reflects a practical, problem-solving approach to challenges that are seen as external to the person's core identity. In this sense, it is functionally similar to the modern English use of “disorder” or “impairment” in clinical contexts.
障碍 is a versatile word used in both formal and informal contexts, though it always implies a significant issue.