Older age (odds ratio (OR) = 1.020; 95% confidence interval (CI) 1.003–1.038; p = 0.018), male sex (OR = 2.169; 95% CI 1.272–3.698; p = 0.004), lower body temperature (OR = 0.506; 95% CI 0.68–0.696; p  <  0.001), C-reactive protein (OR = 1.071; 95% CI 1.023–1.122; p = 0.003), and NLR (OR = 1.082; 95% CI 1.024–1.145; p = 0.005) were significant independent risk factors for DNI in patients with tonsillitis. The gene discussed is CRP; the disease is medical procedure.