My aunt had high blood pressure. Once when she went to the doctor, her pressure was so out of control that the doctor sent her to the hospital because he said she could have a stroke at any moment. After that episode she started taking blood pressure medication and she was able to get her pressure back to where it was supposed to be.
My aunt knew how important controlling her blood pressure was, but for some reason she would stop taking her medications from time to time. One day her daughter noticed my aunt was really confused and could not understand simple things, so she took her to the doctor.
My aunt was put in the hospital again, and after a lot of tests, the doctors said she had had a series of small or mild strokes over a period of time. The strokes left her confused. This was really sad because she was too young to be in the condition she was in. It was like she was suffering from severe dementia. Physically she was fine.