Most of the time, strokes are diagnosed in an emergency situation, not through a normal check-up. However, if you believe that you are at risk for suffering a stroke, your doctor can examine you to determine how susceptible you may be to developing blood clots or broken blood vessels in the brain.  

Medical examination
During a non-emergency appointment, you can first see a primary care physician doctor, who might recommend that you visit a neurologist who specializes in diagnosing and treating victims of stroke, and a neurosurgeon, if necessary.  Internal medicine specialists can detect and treat most of the risk-factors for developing brain stroke, but do not treat victims of brain stroke.

Although a stroke itself gives no warning sign, the tests that your doctor may order are relatively straight-forward, and look for well-known indicators of strokes (e.g. such as a high cholesterol level).  Once you have these tests then your doctor can either treat you immediately for a stroke, or for an increased susceptibility risk of stroke.  S/He will want request several diagnostic tests, including:

Angiography - X-rays with contrast allow your doctor to see blood vessels in your brain and neck. 

Blood test - Used to investigate cholesterol and blood sugar levels.

Carotid doppler or duplex - A carotid ultrasound allows your doctor to see the blood flow/artery wall plaques in carotid arteries in your neck.

Computerized tomography (CT scan) with contrast - X-rays allow your doctor to identify brain tissue that has been damaged by ischemia or hemorrhage.

Echocardiography - Ultrasound images are created which search for heart disorders that can lead to possible for dislodged blood clots from the heart.

Magnetic resonance imaging (MRI) -  A 3-D image of your brain is created using a magnetic field, thus allowing  doctor to look for damaged brain tissue.

Physical examination - Your weight, blood pressure, and history of diabetes will all be indicative factors of increased susceptibility to a stroke.

Emergency stroke diagnosis
Emergency room diagnosis of a stroke may involve all of the tests listed above (blood test, CT scan, etc.).  However, special emphasis may be placed on imaging tests, such as the CT or MRI, to examine pictures that can reveal important information.  ER doctors might be able to notice some signs of stroke also, such as slurred speech or difficulty in responding to conversation. Also, your descriptions of symptoms and history of previous strokes (if applicable) will be important for the doctors. 

Scheduling an appointment with your doctor to determine how susceptible you are to having a stroke is a smart choice.  While a stroke has the potential to debilitate, it is a condition that is preventable.  Communicate with your doctor about your medical history and family medical history to determine the preventative actions and treatments you can begin now to prevent future problems.  To learn more about treatment options, read here to answer the question: how do you treat a stroke.