Concern
Single-Strand Knots
A single-strand knot forms when one curl loops back and knots around itself -- not the same thing as a tangle between multiple strands, and not fixable by ordinary detangling technique alone. They're more common on drier, more porous ends and tend to show up first at the demarcation line for transitioning hair.
Full guide
Single-Strand Knots: Why They Happen and How to Prevent Them
Read itWhy curly and coily hair forms these specific knots
Curly and coily hair grows from an oval-shaped follicle rather than a round one, which is part of why the strand curves and loops as it grows. Sometimes a single strand loops back and catches on itself, tying a tiny knot -- something that's essentially impossible on straight hair. It happens most on ends that are drier or more porous, since rougher, raised cuticle catches more easily than smooth hair does, and shrinkage makes it worse by packing curls more closely together where they can tangle with themselves.
Why a trim is the only real fix
Once a strand has actually knotted, there's no detangling technique that reliably undoes it without risking more damage to the strand -- the standard advice is to trim it off with sharp shears rather than pick or pull at it. Keeping ends well-moisturized and sealed, and detangling gently with conditioner rather than dry, reduces how often new knots form, but it doesn't prevent them completely -- a routine trim (commonly every six to eight weeks) is what actually keeps the count manageable.