Nasal Mucus (Boogers): Formation, Composition, and Clinical Clues

Boogers are dried or semi-solid nasal mucus. They form when mucus traps inhaled particles (dust, pollen, bacteria) and dries.

Composition

• Water (95%)
• Mucins (glycoproteins) – gel matrix
• Trapped particles, dead epithelial cells, leukocytes, antibodies (IgA)
• Bacteria (normal flora or pathogens)

Color Significance

• Clear: normal
• White: congestion, early viral
• Yellow/Green: neutrophil enzymes (infection, viral or bacterial)
• Brown/Black: dried blood, pollution, smoking
• Red: active bleeding

When to Worry

Persistent colored mucus >10 days, facial pain, fever, recurrent epistaxis, or unilateral foul discharge → evaluate for sinusitis, foreign body, tumor.