Tunneling vs. Undermining: Key Wound Care Differences Explained
Tunneling is a narrow channel extending from a wound base into surrounding tissue; undermining is tissue loss beneath intact skin edges, creating a shelf-like pocket.
Nurses chart “tunneling 4 cm” yet skip “undermining 2 cm”; both hide pus and stall healing, so mix-ups delay the right packing and stall discharge.
Key Differences
Tunneling goes deep like a straw; undermining spreads wide like a cave under skin. Measure tunnels with cotton-tip depth; map undermining by clock-face width.
Which One Should You Choose?
If a sinus tract points one way, tunneling rules. If edges lift like a trapdoor, undermining demands broader packing. Choose based on wound topography, not guesswork.
Examples and Daily Life
Think of tunneling as a drinking straw poked into a foam cup; undermining is the lid peeling off while the cup stays intact. Both let coffee leak—just from different spots.
Can a wound have both?
Yes; a sacral ulcer can tunnel 3 cm toward the coccyx while undermining 5 cm under adjacent skin.
Why clock-face notation?
It charts undermining width: “Undermining from 2 to 7 o’clock” tells everyone exactly where to pack.
Does silver packing help both?
Silver manages bioburden in either space, but shape matters: ribbon for tunnels, wider rope for undermining shelves.