Hi
Welcome to the forum!
There are many causes of dizziness, lightheadedness, passing out, blackouts etc. It is difficult to comment without examination. I am just enumerating the possible causes. You can discuss this with your doctor and get yourself examined.
Dizziness could be due to postural hypotension (blood pressure falling with change of position), internal ear problems and cervical spondylitis or compression of cervical spinal nerves. All these cause dizziness when you get up from lying down position or when you change position that results in a change in the level of your head. Cervical spondylitis and ear problems also cause dizziness on changing the position of the neck.
Dehydration, certain medications, heart problems, untreated diabetes, and nervous system disorders can all cause postural hypotension. Certain internal ear problems can also affect blood pressure monitoring by the body by not properly signaling a change in position.
Compression of the spinal nerves in the cervical spine region happen due to overuse of computers, work involving straining of neck, canal stenosis, bone disease, spondylosis, poor posture etc.
Presence of anemia, GERD, hypoglycemia or low sugar and some endocrine problems like underactive thyroid (called hypothyroidism), overactive thyroid (called hyperthyroidism), adrenal insufficiency (called Addison's disease) can also precipitate dizziness. Over exposure to sun can also be a possibility.
Blood pressure monitoring, tilt table test, EKG, heart echo, ambulatory blood pressure recording, MRI of cervical spine, ENT consultation and some blood tests are all required for a diagnosis of your problem.
Hope this helps. Please let me know if there is any thing else and do keep me posted. Take care!
the same thing has happened to me . Im 13. and I get dizzy, nausa, and feel sick, and blurred vision. its probably low blood sugar. because thats what mine is. in the morning, try to eat something, like a glass of juice. you'll feel much better.