What should you know about causes of extreme dizziness?

A spinning sensation triggered by turning in bed or moving the head can occur with benign paroxysmal positional vertigo. Light-headedness after standing, especially with thirst, sweating or illness, may reflect dehydration or heat exhaustion. Shakiness, sweating, hunger and difficulty concentrating can occur with hypoglycaemia. Anaemia or iron-deficiency anaemia may cause dizziness with tiredness, breathlessness or paleness.

A racing, fluttering or irregular heartbeat with dizziness can occur in atrial fibrillation or another rhythm problem. Anxiety can bring rapid breathing, tingling and a sense of unreality. Dizziness is a symptom rather than a diagnosis, and the trigger, duration, position and associated signs help guide assessment.

Sit or lie down immediately, move slowly and avoid driving, heights or machinery until the sensation passes. If heat or fluid loss is possible, cool down and sip fluids if you are alert and able to swallow. If you have diabetes or a known risk of low blood sugar, follow your personal treatment plan. Note the position, activity, duration, heartbeat, hearing changes, headache and medicines around each episode.

Seek urgent help for dizziness with chest pain, fainting, severe headache, new weakness or numbness, trouble speaking, confusion, inability to walk, persistent vomiting or a new irregular heartbeat. Prompt review is also needed when episodes recur, follow an injury, or prevent normal activities. Do not assume severe dizziness is anxiety until other causes have been considered.

Is this spinning, imbalance or near-fainting, and what does that suggest? Could hydration, blood sugar, anaemia, medication or heart rhythm be involved? Would blood pressure checks, blood tests, an ear examination or heart tracing help?