Thanks for the query
Sudden and brief spells of dizziness is noticed in the conditions affecting the brain, the inner ear and sudden fall in the blood pressure.
At this age of yours the most common condition which can cause these symptoms is Transient Ischemic Attack (TIA). TIA is caused due to sudden reduction in the blood supply to certain areas of the brain or spinal cord causing dizziness and weakness of the limbs. The predisposing factors of this condition include Hypertension (increased blood pressure), stress, increased cholesterol, etc.
Another probable cause of this dizziness could be inner ear related known as Benign Paroxysmal Positional Vertigo (BBPV). In this condition an individual experiences dizziness on rolling over the bed or turning the neck on either side or bending.
Finally, sudden reduction in the blood pressure (hypotension) can also lead to brief spells of dizziness, as there is pooling of the blood in the extremities of the body and insufficient blood supply to the brain.
I would advise you to get a thorough evaluation done by a good physician and MRI if possible.
Hope I have answered your query; I will be available for the follow-up queries.
Dr. Naveen Kumar N.