All potted plants may eventually get root-bound, in which the roots hit the sides of the pot and start to grow back in towards existing roots or escape through the drainage holes. Plants absorb most of their water through the growing tips of roots. Thus, root-bound plants will have other water-related problems like wilting or have stunted growth because their root tips will no longer be in contact with moist soil.
Plants have roots growing out of the soil via the drainage hole of a pot, or along the walls of the pot.
Plant growth is slow, or the plant stops growing altogether.
Leaf tips may start to die back due to a lack of water reaching the leaf. Take note that this might also be a symptom of inconsistent watering.
Remove the plant from its old pot and tease part the roots before replanting it in a pot at least 10cm larger in diameter and depth with more soil.