Damage to your brain

Your brain depends on a nourishing blood supply to work properly. But high blood pressure can cause several problems, including:

• Transient ischemic attack (TIA). Sometimes called a ministroke, a TIA is a brief, temporary disruption of blood supply to your brain. Hardened arteries or blood clots caused by high blood pressure can cause TIA. TIA is often a warning that you're at risk of a full-blown stroke.
• Stroke. A stroke occurs when part of your brain is deprived of oxygen and nutrients, causing brain cells to die. Blood vessels damaged by high blood pressure can narrow, rupture or leak. High blood pressure can also cause blood clots to form in the arteries leading to your brain, blocking blood flow and potentially causing a stroke.
• Dementia. Narrowed or blocked arteries can limit blood flow to the brain, leading to a certain type of dementia (vascular dementia). A stroke that interrupts blood flow to the brain can also cause vascular dementia.
• Mild cognitive impairment. This condition is a transition stage between the changes in understanding and memory that generally come with aging and the more-serious problems caused by dementia. Studies suggest that high blood pressure can lead to mild cognitive impairment.