I understand your concern and will do my best to answer your question. Dizziness or lightheadedness is very common in the second trimester. Hormones from the pregnancy drop your blood pressure and the baby is getting bigger, squashing the major veins that return blood to your heart and some people are very sensitive. Should you ever have a black out or complete loss of consciousness, get to the emergency room. If it keeps happening I usually have my patients see a cardiologist for an echocardiogram (ultrasound of your heart) and a Holter monitor (a 24 hour EKG) and almost always they find nothing seriously wrong and nothing needs to be done. It sure can be annoying though, I hear you. In the mean time, try the following: - drink plenty of fluids (8 to 10 glasses of water a day) - avoid nicotine, alcohol, caffeine - don t restrict salt intake - don t stand up suddenly: when getting out of bed or up out of a chair, flex your leg muscles, do isometrics, wiggle your toes - this helps blood get back to your heart I hope that helped and best of luck with the pregnancy