Dizziness: Painless head discomfort with many possible causes including disturbances of vision, the brain, balance (vestibular) system of the inner ear, and gastrointestinal system. Dizziness is a medically indistinct term which laypersons use to describe a variety of conditions ranging from lightheadedness, unsteadiness to vertigo.

People experiencing dizziness may describe it as any of a number of sensations, such as:

A false sense of motion or spinning (vertigo)
Lightheadedness or feeling faint
Unsteadiness or a loss of balance
A feeling of floating, wooziness or heavy-headedness
These feelings may be triggered or worsened by walking, standing up or moving your head. Your dizziness may accompanied by nausea or be so sudden or severe that you need to sit or lie down. The episode may last seconds or days and may recur.

Ear infections and conditions, including labyrinthitis and Ménière's disease, affecting balance
Migraines
Stress
Anxiety
Low blood sugar levels ( hypoglycaemia) that can affect people with diabetes, also called 'hypos'
Blood pressure falling when standing up, called postural hypotension, that can affect older people
Dehydration
Heat exhaustion
Lack of blood flow to the brain, called vertebrobasilar insufficiency
Neurological (brain) conditions, including stroke and multiple sclerosis (MS)
Anaemia
Alcohol abuse
Drug abuse
Side-effects of some medication
Irregular heartbeat
Carbon monoxide poisoning
Head injury
Vision problems, adjusting to new glasses
Sea, air or rail travel - along with travel sickness or motion sickness.

https://www.webmd.boots.com/a-to-z-guides/dizziness-symptoms-diagnosis-treatment
https://www.mayoclinic.org/diseases-conditions/dizziness/basics/symptoms/con-20023004