Head rushes, how can i stop them, and can they cause any brain damage?

Yes: Symptoms such as dizziness, lightheadedness and headaches that occur with change in position (lying to sitting or sitting to standing) are often caused by dehydration or low blood pressure. Start by changing position slowly. In the morning sit on the edge of the bed for a minute before standing. Increase your water intake as well. If the symptoms continue talk to your doctor.