Yes, episodes of stress can result in feeling lightheaded. There are several ways your body and mind might react to stress to cause the dizzy sensation. During an anxiety or panic attack, a person's heart rate can accelerate and the chest pounding can be very uncomfortable. When this occurs, people commonly become quite scared, causing them to sweat and feel like they might pass out.
Another possible reaction is quite different. During a highly emotional circumstance, some people experience a marked slowing of their heart rate combined with a fall in blood pressure. If this happens and the person remains upright, he or she will often faint. This type of fainting spell is called vasovagal or vaso-depressor syncope.
Anxiety and stress, even with no changes in heart rate or blood pressure, can make you feel less in touch with your surroundings. This experience may be perceived as a dizzy or lightheaded feeling. Much less commonly, anxiety or stress can unmask an underlying heart condition or disorder of the nervous system showing itself as dizziness or lightheadedness.
I advise anyone who has lost consciousness (blacked out) to promptly notify his or her physician. Even if you have not lost consciousness, you should contact your health care provider to discuss your symptoms.