Why Drains Clog: Common Causes and What to Check

Drain problems can be caused by many different factors, and the underlying reason matters because the right solution depends on what’s actually blocking the flow. A slow drain today can turn into a full backup if the cause is ignored—especially when multiple fixtures share the same line.
One of the most frequent causes is a buildup of hair and soap residue. In showers and bathrooms, hair can form a mat that traps other materials, while soap scum and shampoo thicken the blockage over time. This often shows up as gurgling sounds or water draining more slowly than usual.