High hemoglobin levels, known as polycythemia, can potentially contribute to an increased risk of blood clots or thrombosis, which may, in rare cases, lead to a stroke. However, it's important to note that multiple factors contribute to the development of a stroke, including underlying health conditions, lifestyle factors, and genetic predisposition. If you have concerns about your risk of stroke or high hemoglobin levels, it's crucial to consult with a healthcare professional for a comprehensive evaluation and personalized advice.