Tonsil stones, or tonsilloliths, are small, white or yellowish lumps that can form in the crypts (folds) of your tonsils. Made from a buildup of dead cells, food debris, mucus, and bacteria, these formations calcify over time, resulting in a gritty, foul-smelling lump often discovered unexpectedly — like after coughing or sneezing.

These stones typically look like small grains of rice or popcorn and often carry a strong odor due to sulfur-producing bacteria. While many go unnoticed, larger ones can cause bad breath, sore throat, difficulty swallowing, ear pain, and a sensation of something stuck in your throat.