The most significant
risk factor for stroke is
high blood pressure. Other risk factors include
high blood cholesterol,
tobacco smoking,
obesity,
diabetes mellitus, a previous
TIA,
end-stage kidney disease, and
atrial fibrillation. Ischemic stroke is typically caused by blockage of a blood vessel, though there are also less common causes. Hemorrhagic stroke is caused by either
bleeding directly into the brain or
into the space between the
brain's membranes. Bleeding may occur due to a ruptured
brain aneurysm. Diagnosis is typically based on a
physical exam and supported by
medical imaging such as a
CT scan or
MRI scan. A CT scan can rule out bleeding, but may not necessarily rule out ischemia, which early on typically does not show up on a CT scan. Other tests such as an
electrocardiogram (ECG) and
blood tests are done to determine risk factors and possible causes.
Low blood sugar may cause similar symptoms.