Sickness radical
疒 — a person leaning on a sickbed. The indexing radical, marking
瘫 as a disease term, specifically paralysis (
瘫痪). The same wrapper groups
瘫 with
病 (illness),
痛 (pain),
疯 (mad),
痪 (paralyzed) — most of the body's pathology vocabulary lives under this roof.