What can cause sudden dizziness?

Many things. The cause of your dizziness can only be determined by a careful history in regards to what you experience when you feel dizzy, how long it lasts, what other symptoms it is associated with you. The determination begins with your doctor.
BPPV. Benign paroxysmal positional vertigo is a n inner ear problem where the crystals inside the ear are dislodged and then caught in the semi-circular canals causing the dizziness. Other possibilities are: low blood pressure, low blood o2, low blood sugar, or hyperventilation, yo name a few.

Related Questions

What can cause sudden blindness, dizziness, difficulty breathing, and stumbling?

Symptoms. Various kinds of poisoning can cause those symptoms including alcohol, combinations of causes also. Those things you mentioned all are bad and should be seen by a doctor as soon as possible to try and determine causation.

What can cause sudden and random weakness, dizziness nausea and shaking lasting from 5mins to hours. Not blood sugar, BP or PG can get palpations also?

IF all medical. Conditions are ruled out consider panic disorder. Please see a mental health professional. Please do not use medication only but get training in how to manage panic attacks. IF this is what you are dealing with, they are very treatable. Peace and good health.