Please avoid sudden changes in activity level. Any time you have been inactive for a period of time, like sitting in front of the TV or sleeping, you need to give your body time to adjust to the changes in activity level. This is because your heart is not as strong as it used to be and needs extra time to increase from a resting state to an active state. Giving yourself some extra time to adjust to the changes will allow the heart to keep your brain properly supplied with blood reducing your chances of falling from dizziness.
For example be careful getting out of bed. When you need to get out of bed, first sit on the edge of the bed for a minute or two before you stand up. Then start walking slowly.