Strokes are usually diagnosed by carrying out physical tests and studying images of the brain produced during a scan. When you first arrive at hospital with a suspected stroke, the doctor will want to find out as much as they can about your symptoms. A number of tests can be carried out to help confirm the diagnosis and determine the cause of the stroke. This may include: blood tests to determine your cholesterol and blood sugar levels. checking your pulse for an irregular heartbeat. taking a blood pressure measurement.