Thank you for your query on Healthcare Magic.
This type of presentation is seen with syncope
which usually occur with prolonged standing.
But an underlying heart rhythm abnormality known as cardiac arrhythmias has to be ruled out by examination with a physician.
Investigations like ECG, 2D Echo is required to assess the heart rhythm and cardiac function.
Consult the physician as early as possible for further evaluation and management.
Hope I have answered your query.