Iron deficiency anemia (IDA) has been associated with strokes in young people. IDA doesn't necessarily have pronounced symptoms and a diagnosis with a blood sample is simple and cheap. It is often considered a "female disorder" but it's only slightly more common in females than males.
tldr: Have your blood checked.
[1] https://www.hindawi.com/journals/crinm/2012/487080/
EDIT: As most follow up comments seem to center around diet as a cause, I wanted to point out that there are several other causes.