Brief Answer:
It can be cardiac Syncope, neurological event or postural drop

Detailed Answer:
Hi! Welcome to health care magic!

Thanks for sharing your concerns. As far as sudden loss of where abouts or black outs with dizziness are concerned it can be due to variety of causes.

First of all, sudden drop in blood pressure which is called postural drop may be a reason which is a sign of low volume conditions or autonomic neuropthies. For these yiu need to have sitting and standing blood pressures to monitor variation between the two.

It can be cardiac Syncope during to sudden disturbances in the heart beats, called arrythmias for which you need to have an EKG. Also in some cases 24 hour Holter monitoring may be needed.

Any fluctuation of blood supply to brain can cause this, for which you need to have doppler ultrasound of neck vessels to look for any plaque or clot blocking the blood flow.

Brain imaging and EEG may be needed for abscence seizures or any mass effects inside Brain or TIA assessment. A MRA may needed to look for brain blood supply and any small aneurysm present in brain circulation.

Meanwhile before jumping to such invasive or extensive lab workup baseline labs to look for Complete blood count, ESR, electrolytes, calcium, phosphate, magnesium, thyroid function tests and blood sugar random need to be done.

For detailed evaluation or cause in your case, visit a neurologist and get a detailed examination and streamline work up accordingly.

Hoping you a speedy recovery. If you have any more questions, feel free to ask. Regards.

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