Hello dear,
In your post, you have not mentioned about any past history of Diabetes,
Hypertension, Thyroid disorders, etc. in your husband.
Under such circumstances, the symptoms as mentioned in your post can be attributed to pathology in the Vestibular Apparatus in inner ear (it is associated with maintenance of body posture & balance) most probably
Labyrinthitis or Benign Paroxysmal Positional Vertigo.
Symptomatic relief can be obtained with intake of Vestibular sedatives like
Betahistine or
Cinnarizine preparations (to be taken only under the guidance of a Physician).
If it still persists, then you need to consult his Physician/
ENT Specialist & get a complete clinical examination done.
Investigations like estimation of blood pressure, blood sugar levels, serum electrolytes & vestibular function tests will be required to rule out any pathological cause for the symptoms.
There is no need to worry, he will be fine.
Till then, he should maintain adequate hydration & proper nutrition status and avoid stress.
And also take precautions of getting up from bed slowly & avoid sudden head movements.
Wishing him a Good Health.
Take care.