It causes your marrow to make too many red blood cells so your blood is too thick. You may be more likely to have clots, a stroke, or a heart attack. This disease gets worse slowly, usually over ...

While it’s well-known that issues like high blood pressure, diabetes, smoking and not enough exercise are risk factors for a ...

but too many of them can make your blood thicken and form clots. Sometimes blood clots lead to a heart attack or stroke. Treatments lower the number of red blood cells and prevent blood clots.