Autoimmune Disease Diagnosis Market size was valued at USD 3.9 billion in 2025 and is projected to cross USD 6.7 billion by the end of 2035, expanding at more than 5.7% CAGR during the forecast period, i.e., 2026-2035. The North America’s industry market leadership by 2035, with a 38.4% share, is supported by strong awareness and early diagnostic adoption.