Feelings of lightheadedness and dizziness, while similar, are not interchangeable and often have different causes. Dizziness is a feeling of being off balance or being in motion while not actually in motion, and is sometimes caused by inner ear or more serious neurological problems. These issues should almost always require a doctor’s attention and may need a VNG or Videonystagmography test. Lightheadedness, by comparison, is the term usually given to the act of feeling like you are ready to faint, and can be caused by a large variety of issues, many of them benign.
One primary cause of lightheadedness is a disruption, or sudden change, in the flow of blood to the brain. When the brain is deprived of blood, it is not able to function as it should, thus the feelings of being disoriented or about to black out. This disruption can be caused by something as simple as a sudden change in position, like sitting up abruptly after laying down. If you have a predisposition for issues with low blood pressure or circulation, sometimes causing persistent issues like cold hands and feet, you may be more likely to have a spell of lightheadedness.
Another cause can be dehydration. While this is especially common in very hot temperatures, even for people who do not sweat much, a large variety of other triggers can cause dehydration. Alcohol can deprive a body of water, which is what causes the intense headaches and sickness of hangovers, as can excessively salty foods. Smoking in all forms as well can have a very drying effect on the body, especially in the throat, and many ailments such as colds and flus can increase the body’s need for water.
Before you talk to your doctor, keep careful track of when, for how long, and how often you have a feeling of lightheadedness. If they are short, infrequent episodes accompanied by some of the triggers above, try changing your routine to increase your water intake and avoid sudden movements of the head. If they are severe, persistent, or not linked to any of the conditions about, consult your physician and consider neurological imaging and tests, such as VNG tests or CAT scans, to rule out a more serious issue.