have had sleepiness for over year since oct 2010 dizziness and vision problems that come before dizzy episode. bp is low have seen cardiologist due to low bp  had a bad dizzy spell while talking to someone follwed by getting better and then whole body started shaking for a min while standing...since then headache feel off balance visually and walking
This isn't quite enough information to judge from. However, symptoms with low blood pressure tie the two together and pursuing the reason for low blood pressure is reasonable. The causes may be hormonal, nerve dysfunction and of course medication. Start back with your primary doctor and bring a record of blood pressures taken on a schedule, once or twice a day, not just while you feel bad. Take the blood pressure seated and after standing for two minutes. This may help him or her see the problem.