Brief Answer:
Vertigo, orthostatic hypotension, anemia

Detailed Answer:
Hello,
Thank you for your query,
I'm Dr. Shuba Hariprasad and will be answering your query today.

Your symptoms do indicate a fluctuation in blood pressure and would lead me to primarily rule out orthostatic hypotension, vertigo and anemia.

Would you please clarify a few things for me?
-what is your height and weight?
-do you have any medical problems or take any medications?
-why do you reduce salt intake? Did you suspect a high blood pressure?
-does it seem like the room spins or does it feel like you spin?
-do you have regular menstrual cycles? Any heavy bleed or clots?
-could you be pregnant?

I recommend :
-a physician consult

-blood pressure monitoring three times a day in ideal circumstances (quiet environment, about 2 or more hours after meals and caffeine, lying down quietly for 10 minutes).
After this, sit up on the bed and check your pressure right away and after 10 minutes of sitting).
If you feel giddy or light headed, lie back down and sit up slowly after a few minutes.
If you don't have a pressure monitor, get one as this will aid in monitoring what exactly is going on. Ask your doctor or a nurse to show you the correct way it is to be used.

-an ECG (electrocardiogram)

- blood tests (complete blood count, peripheral smear, electrolyte levels, kidney function tests, Thyroid hormone imbalances )

-urine analysis (to check for proteins)
-a CT scan of the brain, and an echocardiogram if indicated (based on above tests and clinical findings)

Diluting your blood can also cause giddiness. The whooshing sound is that of blood rushing to your brain.

In the meantime :.
-take normal amount of salt, and water. Don't drink more than 3 liters a day unless you feel thirsty or urine is concentrated.
-when you stand from a sitting position or sit from a lying down position, do it gradually. Turn to oneside while lying down and slowly sit up.
-don't turn your head sudden from left to right or up to down.
-avoid driving till we figure out what is going on
-don't sit for too long, stand and walk every 15 minutes. Same goes for when you are standing in one place too long.

If you have any chest discomfort, breathing difficulty, persistent giddiness or headaches, unexplained sweating or vomiting, please go to the ER right away.

Hope this helps.
Please let me know if there is anything else I can help you with.

Wish you good health.
Regards,
Dr. Shuba Hariprasad

---