Thank you for your query at DoctorSpring.com
I understand your concern.
From your description, it seems like you developed an episode of postural hypotension, where there is sudden fall of blood pressure on changing the posture, such as standing up from sitting down position, or standing up suddenly after a long nap, getting up from squatting position, e.t.c . The symptoms include light headedness, giddiness, feeling of loss of conciousness. It can last from 5 seconds to even a minute in extreme cases.
One such isolated episode does not need any further investigations or a visit to the doctor.
However if it recurs again, you need to get your BP monitored and also if possible check your sugar levels.
Feel free to discuss further,