First of all, for patients with no previous history of hypertension, a low-grade fever usually does not lead to an increase in blood pressure, but for patients with a clear history of hypertension, a low-grade fever can lead to a recurrence of hypertension or to a further increase in blood pressure because a low-grade fever is usually caused by a bacterial, viral, or atypical pathogen infection such as Mycoplasma or Chlamydia, and these substances release inflammatory mediators such as interleukin-6, interleukin-10, leukotrienes, and bradykinin. Chlamydia, the body releases inflammatory mediators such as interleukin-6, interleukin-10, leukotrienes, and bradykinin, which in the body cause a rise in the temperatures of the central neuron’s tuning points, which can trigger a low-grade fever. In this case, the sympathetic nerve tone will also increase, therefore, it will lead to a rise in blood pressure, a faster heart rate, and an increase in myocardial contraction, so that patients with low fever will develop high blood pressure.