Why do I feel light headed when I stand up?

Lightheadedness is a concerning symptom. I would recommend that you see your primary care doctor to have this evaluated. While there are some causes that are minor, there are some very serious causes which should be ruled out. When someone feels lightheaded, we often worry if this is because of a low blood pressure. Known as presyncopal symptoms, the feeling of lightheadedness can arise from not enough blood getting to the brain. Specifically, lightheadedness with standing is known as orthostasis. This can be a sign of many serious conditions including anemia, dehydration, serious infection, severe diabetes, heart rhythm problems and heart muscle problems. These conditions are very concerning as (obviously) not enough blood to his head is concerning. Your blood pressure should be checked. The feeling of lightheadedness can also be caused by other problems outside of low blood pressure. Inner ear problems are common. Benign Positional Vertigo (BPV) is common due to problems in the inner ear that causes vertigo type symtpoms with movement. Other hormonal problems like low synthroid dosing or severe diabetes can be responsible. These should be checked. See your doctor. This should be evaluated as the concerning causes (infection, heart troubles) should be ruled out. If your symptoms worsen, go to the doctor or emergency room right away.