Hi, Symptoms you have narrated may be due to- 1) Hypoglycemia : low blood sugar level. There is possibility that you have not consumed anything prior to ultrasound that may lead to low blood sugar level. In your case you felt better after drinking water and proper aeration. Tough possibility of hypoglycemia is there, it is unlikely as symptoms of hypoglycemia get corrected after eating calorie containing food and not by simple water. 2) Transient hypotension : low blood pressure. Though the fluctuation in Blood pressure as figures given by you can be considered as absolutely normal in asymptomatic person. Also symptoms of hypo-tension can be relived with water, as in your case. 3) Postural hypotension: fall of blood pressure in standing position there are many causes for that but most common is dehydration (excessive loss of water from body), this may be due to excessive sweating, loose motions, vomiting, inadequate water intake. Symptoms improves after drinking water and aeration. 4) Suffocation: Lack of proper ventilation, as in over crowded places or in closed room. 5) You have not mentioned for what you have under went ultrasound and what is its report. As other underlying illnesses can also gives similar complaints. 6) Neurological events like TIA (Transient ischemic attack) ie. decrease in blood supply to brain can also give rise to similar complaints. Though it can be present in absolutely normal individual, in most of the cases risk factors always present like advanced age, presence of high blood pressure, diabetes, smoking, cholesterol problems, family history of similar problem. 7) Medicines: certain medicines can give rise to these kind of symptoms. In your case you have not mentioned your age, prior medical history, current indication for ultrasound and its report, any other investigations done. For better opinion all this information is necessary. If you are a healthy young adult without any prior medical illness and was fasting on the day of event and these were your only events, you can wait to seek medical attention.