Concise answer
Hairlines are naturally asymmetric, and pattern loss may progress unevenly. Traction, styling habits, scarring inflammation or previous procedures can also create a one-sided change.
A single photograph cannot show whether the difference is stable, naturally shaped or actively progressing.
Examination looks for miniaturised hairs, scalp change and matching loss elsewhere before restoration options are discussed.
When evaluation may help
Prompt review is appropriate when recession is rapid, sharply localised, painful, itchy or associated with redness, scale or loss of follicular openings.