Brief Answer:
different possible causes

Detailed Answer:

Hi,

The sensation that you are describing is called vertigo and it is due to different possible causes.

It can be central- meaning it is due to an issue with the brain ( eg a type of migraine called vestibular migraine or due to MS or a lesion in a part of the brain called the cerebellum or the brain stem)
The cerebellum and brain stem are different areas of the brain but both can affect balance.

Most commonly though, vertigo is NOT related to anything to do with the brain. It is due to conditions of the inner ear. The ear is made up of three areas- the outer ear, middle ear and inner ear.
Only the outer and middle ear are visible during examination.

The inner ear is not seen by assessment but it plays a big role in balance.

The inner ear causes are- BPPV (benign paroxysmal positional vertigo) , Meniere's disease, vestibular neuritis, immune mediated inner ear disease.

Basically it is thought that- (1) Episodic (comes and goes after a while) vertigo that lasts for days, associated with nausea. No other ear symptoms or symptoms of brain lesions ( difficulty speaking, blurred vision, weakness)---LIKELY DUE TO VESTIBULAR NEURITIS

(2)Episodic vertigo that last for seconds and may be worse with certain head or body positions, can have nausea- DUE TO BPPV

(3)Vertigo that lasts for hours, associated with hearing loss or/tinnitus (ringing or other noises in the ear) DUE TO MENIERE'S DISEASE

Based on what you said, it may be BPPV. The fact that it occurs when you move about on waking may mean that affected by position.
Your doctor can show you a maneuver called Epley maneuver, that helps with this particular cause

You may need to be reviewed by an ENT specialist or Neurologist to find the cause.Imaging by CT or MRI to make sure that not related to any serious cause, may be needed if worsens.

There are meds that can be used for a short time that may help eg anti vert, valium, dramamine

I hope this helps, feel free to ask any other questions

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