Arterial hypertension is a very common disease, which acts as a risk factor for a number of other diseases. Experimental data in rats indicate that chronic arterial hypertension may be associated with a state of resistance to mortality from sepsis. Published data on human arterial hypertension and sepsis do not indicate that the former might act as a protective factor for the outcome of the latter, although precise data on this point have not yet been obtained. On the contrary, the presence of any of a variety of comorbid conditions, and perhaps also the combination of hypertension, old age and a higher prevalence of cardiac disease, may lead to worse outcomes in sepsis and septic shock. The prevalence of arterial hypertension in sepsis patients seems to be increasing while mortality may be decreasing, data consistent with a possible protective role for hypertension in sepsis patients. Black people in the Americas tend to have higher blood pressure than black people in Africa and than whites. If hypertension also acted as a state of resistance to mortality from sepsis in humans, it might provide part of the solution for the mystery of the high prevalence of hypertension in black people in the Americas, since blacks there may be descended from people heavily exposed to infectious diseases.