An obstacle is an object that makes it difficult for you to go where you want to go, because it is in your way. 障碍物
noun [专属名词]障碍,阻碍;障碍物
You can refer to anything that makes it difficult for you to do something as an obstacle. 障碍• Overcrowding remains a large obstacle to improving conditions. 过度拥挤仍然是改善条件的一大障碍。