thanks for your query at HCMlightheadedness
and headache can be due to changes in blood sugar and blood pressure levels.
get blood glucose
levels random, fasting and postprandial levels, and also check your blood pressure .
these are basic things that you need to do first, if these things turn out to be normal further investigation might be needed.
vision examination is also needed sometime visual defects can cuase similar symptoms.
hope this will help you