Which condition can result from untreated high blood pressure?

The correct response highlights the potential consequences of untreated high blood pressure, specifically cognitive decline. When high blood pressure goes unmanaged, it can lead to damage in the blood vessels, including those that supply blood to the brain. This can impair cognitive functions over time, potentially resulting in conditions such as vascular dementia or other forms of cognitive impairment. The consistent stress on the vascular system from high blood pressure can hinder normal blood flow, affecting brain health and leading to gradual declines in memory and other cognitive abilities.

The other options, on the other hand, imply positive health outcomes that are not associated with high blood pressure. Improved lung capacity and increased heart efficiency suggest benefits that are not seen with untreated hypertension, where the heart may actually struggle more due to the increased workload. Additionally, untreated high blood pressure generally increases the risk of stroke, rather than lowering it, as this condition can contribute to the formation of clots and other factors that heighten this risk.