Drains & clogs

Bathroom sink drains slowly

A slow bathroom sink drain is almost always a clog of hair, soap scum, and toothpaste residue building up in the pop-up stopper and the trap just below it.

Difficulty
Easy
Time
15–30 minutes
DIY cost
$5–$15
Pro cost
$100–$180

Symptoms

  • Water swirls and empties slower than normal
  • Standing water lingers around the drain
  • Gurgling as the sink finally empties
  • Smell near the drain

Likely causes

  • CommonHair and soap scum around the pop-up stopperThis is the single most common cause in bathroom sinks.
  • CommonBuildup in the P-trap under the sinkSoap and toothpaste residue collects in the curved trap over time.
  • PossibleMineral scale narrowing the pipeHard water areas see gradual narrowing inside older pipes.
  • Less commonClog further down the branch drain lineMore likely if multiple fixtures are slow together.

What to do

  1. Remove the pop-up stopper (usually lifts out or unscrews after loosening the pivot rod under the sink) and clean off hair and gunk.
  2. Use a flashlight to look into the drain opening for visible buildup and remove what you can with a gloved hand or bent wire.
  3. Try a zip-style drain tool (a plastic barbed stick) pushed a foot or two down the drain to pull out hair clumps.
  4. Flush the drain with hot water for a minute to help clear loosened residue.
  5. If still slow, use a plunger with the overflow hole covered by a wet rag to create suction and plunge several times.
  6. For a persistent clog, use a small hand-crank drain snake through the drain opening after removing the stopper.
  7. Reinstall the stopper and run water to confirm normal drainage.
  8. Avoid pouring chemical drain cleaners repeatedly, since they can damage old pipes without fixing the underlying clog.

Tools and parts

  • Zip-style drain tool
  • Plunger
  • Hand-crank drain snake
  • Flashlight
Plastic zip drain cleaning toolSearch: “plastic barbed drain cleaning tool”

When to call a pro

Call a plumber if a hand snake and plunging don't restore normal flow, since the clog may be further down the line.

Safety

Generally low risk

Generally low risk for a careful person. Stop if anything looks different from what this guide describes.

Related guides

Operator provides AI-generated troubleshooting information. It can be wrong. For safety-critical, electrical, gas, structural, medical, automotive safety, or other high-risk problems, consult a qualified professional.