To investigate the correlation between postural blood pressure changes and the complications of neurodegenerative diseases in elderly patients over 80 years old who were diagnosed with hypertension. Methods: A multicenter cross-sectional study was conducted among very old patients (≥80 years) with hypertension using questionnaire-based surveys at 28 Grade A tertiary Hospitals. A total of 1562 subjects aged between 80 and 105 were enrolled in this study. Blood pressures were measured in the sitting position, the supine position and the upright position within 3 minutes of standing. Results: In a total of 1562 subjects, 387 patients were diagnosed with orthostatic hypotension (OH), the other 1175 patients were diagnosed with non-orthostatic hypotension (NOH). The prevalence of OH was 24.8% . OH patients had higher rates suffering from neurodegenerative diseases than NOH patients. The results of a logistic regression analysis indicated that Alzheimer's disease and Parkinson's disease were both positively correlated with the prevalence of OH. Conclusion: The prevalence of OH is high in elderly hypertensive patients over 80 years old. Elderly hypertensive patients complicated with neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease are likely to develop OH.