Can you fix a dropped stitch?
To begin rescuing the dropped stitch, spread out all the stitches on your needle so that the loose strands of yarn above the dropped stitch are stretched out and clearly visible. Then, use another needle (preferable a doubled pointed needle) to pick up the dropped stitch.
What happens if you don’t pick up a dropped stitch?
Every knitter drops stitches. If you didn’t notice it fall, you might end up knitting several rows before you see the tell-tale ladders of yarn filling the gap where the stitch was dropped.