Time is critical when diagnosing a stroke. A quick diagnosis within the first 3 hours may enable your doctor to use medicines that can lead to a better recovery.

The first priority will be to determine whether you are having an ischemic or hemorrhagic stroke. This distinction is critical because the medicine given for an ischemic stroke (caused by a blood clot) could be life-threatening if the stroke is hemorrhagic (caused by bleeding). Your doctor will also want to rule out other conditions that have symptoms similar to a stroke and to check for complications.

The first test after a stroke is typically a computed tomography (CT) scan of the brain, which is a series of X-rays of your brain that can identify whether there is bleeding.¹ This test will help your doctor diagnose whether the stroke is ischemic or hemorrhagic. Magnetic resonance imaging (MRI) may also be done to determine the amount of damage to the brain and help predict recovery.

Other initial tests recommended for ischemic stroke include:¹

• Electrocardiogram (ECG, EKG) to check for heart problems, including arrhythmias and atrial fibrillation.
• Blood tests, such as a complete blood count (CBC), blood sugar, electrolytes, liver and kidney function, and prothrombin time (a test that measures how long it takes your blood to clot). These tests are done to help your doctor make choices about your treatment and to check for conditions that may cause symptoms similar to a stroke.

If your doctor suspects or other tests indicate narrowing of a carotid artery, he or she may want you to have a carotid ultrasound/Doppler scan to evaluate blood flow through the artery. Your doctor may also request magnetic resonance angiogram (MRA), CT angiogram, or carotid angiogram.

If your doctor believes the stroke may have been caused by a problem with your heart, an echocardiogram or Holter monitoring or telemetry test may be done.

Guidelines recommend that risk factors for heart disease also be assessed after a stroke to prevent disability or death from a future heart problem.⁸ This is because many people who have had a stroke also have coronary artery disease.