Hi
Welcome to the MedHelp forum!
Blood circulation is ideally checked by a vascular specialist by sending you for either angiograms or duplex ultrasounds.
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.
Other causes are anemia, claustrophobia, GERD, hypoglycemia or low sugar and some endocrine problems. Endocrine problems, such as an underactive thyroid (called hypothyroidism), overactive thyroid (called hyperthyroidism), adrenal insufficiency (called Addison's disease), low blood sugar levels, and in some cases, diabetes, may lead to hypotension and hence lightheadedness and an off balance feeling.
Certain types of epilepsies and seizures too can cause similar symptoms. If you have an accompanying headache then you must also look at benign intracranial hypertension. Heart problems too should be ruled out in your case. If all other tests are normal, maybe an ECHO should be done to rule out mitral valve prolapse. Patent foramen ovale too could be the cause (commonly known as hole in the heart). It can also be chronic fatigue syndrome if all other causes are ruled out. A brain lesion too can cause dizziness but often there are other neurological signs such as numbness, tingling, loss of function of a limb etc.
Anemia could be a cause and so also hypoglycemia. It can also be severe acidity. Take a multivitamin pill. Eat at regular intervals. Take Omeprazole empty stomach in morning and an antacid gel at bedtime. Refrain from smoking, alcohol, fuzzy drinks, caffeine, and spicy food. See if this helps. Also get your BP checked to see if it is not too high or too low. It can also be stress and lack of proper sleep. If it does not then you will have to consult a doctor to re-evaluate to rule out thyroid problems, ear problems, pinched cervical spinal nerves, epilepsies, heart problems, etc. Take care!