I'm lightheaded and faint when changing positions in bed, moving whatsoever, moving my arms around, lifting my arms, lifting my legs, pushing myself up on the bed, pushing and pulling anything, lifting, standing up, walking, talking too much, laughing, or just having a vasovagal response or reflex. I have had this problem for many years, however, it got worse after being deconditioned. My muscles became deconditioned because of a very sedentary lifestyle, which was due from me having severe lung issues as well. I have 30% lung capacity. But I would like I had it before I even learned about my lungs or even had major symptoms. Little lightheaded is just natural for me, but it has gotten much worse through the years, after being D condition. It is a catch 22 in my case. I believe it is lack of oxygen to the brain. This could be due for an adequate blood flow to the brain, caused by blocked arteries or aneurysm or cyst or tumor. However, it could be also be called simply due to sedentary lifestyle. That way the blood does not get pumping the way it should. Or, it could be from a bad heart. If the heart is weak, or if it is not pumping the blood correctly, the oxygen will not reach the brain. And don't even go by the pulsometer. That thing only reads the oxygen in your fingertips. You need an arterial blood gas sample which basically tests the blood oxygen level in your big arteries. Also an ultrasound of your brain would help. MRI of your brain as well, MRA as well. Stay away from ct cans because they can cause you cancer. Get your heart checked with an echocardiogram and a stress test. It is very essential. You could have something going wrong with your heart, lungs, or both. The heart and lungs work synonymously with each other.