Why does a bathroom sink drain clog?

Hair and toothpaste are the main causes. Hair tangles around the pop-up rod and collects in the drain; toothpaste residue mixes with soap and hardens. Remove the pop-up first, then snake or clean the P-trap.

Can I fix a clogged bathroom sink myself?

Yes. Most bathroom sink clogs are in the pop-up area or P-trap. Remove the pop-up, pull out hair, snake the drain, and clean the P-trap. Call a plumber if the snake hits a hard stop or water backs up from other fixtures.

When should I call a plumber for a bathroom sink clog?

Call a plumber if the snake hits a hard stop, water backs up from the tub or toilet when you run the sink, or you smell sewage. Those signs suggest a main-line blockage.

Search guides

Fix a bathroom sink drain that is clogged

We'll remove the pop-up, clear hair and toothpaste buildup with a snake, and clean the P-trap—or tell you when to call a plumber.

Category: Troubleshooting · Home plumbing
Time: 15–45 min
Last reviewed: Mar 6, 2026

What you'll need

Cup plunger (not flange)
Hand-crank drain snake
Bucket, towels, needle-nose pliers, channel-lock pliers

Quick triage — pick your path

Get started

Choose the option that matches what you see. You can jump straight to that section.

Follow this guide Work through the full procedure from confirming the symptom to cleaning the P-trap.
Remove pop-up and snake You want to start with the pop-up and snake before the P-trap.
Clean the P-trap The snake did not clear it; you need to inspect and clean the P-trap.
When to call a plumber The snake hits a hard stop, water backs up from other fixtures, or you smell sewage.

Show full guide

Steps

Goal: Confirm the symptom, remove the pop-up, clear the clog with a snake or P-trap, or call a plumber when needed.

Run the faucet and watch the basin. If water pools and drains very slowly or not at all, you have a clog. Check that the issue is only this sink—if other fixtures back up when you run it, the clog may be in the main line.
Good: Water pools or drains very slowly in this sink only—local clog. Proceed to Remove pop-up and snake.
Bad: Other fixtures back up when you run this sink—main line or shared drain. See When to get help.

Goal: Remove the pop-up, pull out hair and toothpaste, then snake the drain.

Twist the pop-up stopper counterclockwise and lift it out. Pull out hair and debris with needle-nose pliers. Run water and check if flow improves.
If still slow, use a cup plunger, then flush with very hot tap water (or boiling for metal pipes; only hot tap for PVC).
Feed a hand-crank drain snake into the drain until you feel resistance. Crank clockwise to bore through or hook the clog. Pull back slowly—debris on the tip means you reached the blockage. Run water and confirm flow.
Good: Flow improved or debris on the snake—clog cleared. See Verification.
Bad: Snake hits a hard stop or still slow—proceed to Clean the P-trap or call a plumber.

Clean the P-trap

Goal: Remove and clean the P-trap; reassemble and test.

Place a bucket under the P-trap. Unscrew the slip nuts on both ends by hand or with channel-lock pliers. When the trap drops free, dump its contents into the bucket.
Look through the trap and pipe stubs—you should see daylight or light from the other end. Reassemble finger-tight, then snug a quarter turn with pliers.
Run water at full volume for 60 seconds. Check that no drips appear at the slip nuts and water drains freely.
Good: Water drains quickly and joints stay dry. See Verification.
Bad: Water still pools or snake hit a hard stop—call a plumber.

When to get help

Call a plumber if:

The snake hits a hard stop that will not budge.
Water backs up from the tub or toilet when you run this sink.
You smell sewage.

Do not force the snake—you can damage pipes.

Verification

The sink drains at full speed when you run the faucet.
No pooling in the basin after 60 seconds of full flow.
No drips at the P-trap slip nuts. Install a drain screen to prevent future clogs.

Escalation ladder

Work from the device outward. Stop when the problem is fixed.

Confirm symptom Verify the sink drains slowly or not at all; rule out other fixtures.
Remove pop-up and debris Pull out hair and toothpaste from the stopper and drain opening.
Plunger and hot water Try plunger and hot water flush; both can loosen soft clogs.
Drain snake Snake the drain to break through or hook deeper blockages.
Clean P-trap Remove and clean the P-trap; reassemble and test.
Call a plumber Snake hits hard stop, water backs up from other fixtures, or sewage smell—call a pro.

What to capture if you need help

Before calling support or posting for help, have these ready. It speeds everything up.

Whether the sink drains at all
Whether other fixtures back up when this sink runs
Steps already tried (pop-up, plunger, snake, P-trap)
Whether the snake hit a hard stop

Does the bathroom sink drain slowly or not at all?

Run the faucet and watch the basin. If water pools and drains very slowly or not at all, you have a clog.

Run the faucet. Good: water pools or drains very slowly—local clog. Bad: other fixtures back up when you run this sink—main line or shared drain; call a plumber.

Yes No