This article examines the relationships between allergic rhinitis and hypertension, chronic sinusitis and hypertension, and asthma and hypertension. Previous studies have demonstrated that men reporting seasonal or chronic rhinitis had on average a 3.5 mm Hg higher systolic blood pressure than those without allergic rhinitis. Proposed mechanisms to the relationship between allergic rhinitis and sinusitis with hypertension may lie in the pathway of obstructive sleep apnea via neurohumoral responses to hypoxemia. Asthmatics were 1.4 times more likely to have heart disease, and 1.3 times more likely to have high blood pressure, than non-asthmatics. The commonality of immunological dysfunction and inflammation between diseases of allergy and those mediated by hypertension and other vascular disorders may explain the correlations observed. Interestingly, obese individuals have higher levels of circulating IL-6, leptin and TNF-alpha skewing the immune system toward the allergen-reactive type 2 helper T-cell. This would mean that obese individuals were predisposed to diseases of chronic inflammation. The implications of allergic rhinitis, chronic sinusitis, and asthma deserve closer attention, especially into the possibility of co-morbidity for hypertension. Although associations between allergic diseases and hypertension have been reported, more studies need to be performed to elucidate the mechanisms behind such associations. (Cardiol J 2010; 17, 5: 443-447)