A sensation of dizziness and a feeling of being about to faint or lose consciousness. Lightheadedness is a common symptom of orthostatic hypotension, a drop in blood pressure with a change in position (usually from lying down to sitting or standing). It is a good idea to pause for a few moments when changing position, to let the body stabilize. Lightheadedness is a common, mild, and usually harmless side effect of many anti-parkinson’s medications. The greatest risk of lightheadedness is loss of balance that causes a fall. Other factors that can cause or contribute to lightheadedness include low blood sugar level that results from inadequate food intake.