Hello, Thanks for posting your query. Dizziness and lightheadedness is caused by long standing because it may lower your blood pressure. It can be triggered by anti-hypertensive drugs you have been taking. Sometimes it can be due to dehydration and anemia, as you have low iron levels you must be checked for anemia. Take plenty of water, avoid long standing. It is better to take anti-hypertensive drugs before going to bed. You may talk to your doctor if he thinks about changing the dosage of drugs. Hope it helps. Take care.