What causes dizziness?

A spinning sensation may point towards the balance system in the inner ear, including benign paroxysmal positional vertigo, which can be triggered by turning or tilting the head. Lightheadedness when standing can happen when blood pressure briefly falls, or when fluid, blood sugar or oxygen delivery is insufficient. Unsteadiness can relate to vision, muscles, nerves or medicines.

Anaemia and iron deficiency anaemia can reduce oxygen delivery and cause tiredness with lightheadedness. Dehydration, heat exhaustion, anxiety and hypoglycaemia are other possibilities. Palpitations or an irregular pulse may occur with atrial fibrillation. The timing, trigger, duration and accompanying symptoms help a clinician narrow the cause.

Sit or lie down straight away and rise slowly once the feeling passes. Avoid driving, climbing or operating machinery while dizzy. Sip fluids if you may be dehydrated, eat a regular snack if you have missed a meal and can swallow safely, and move to a cool place after heat exposure. Keep a note of triggers, medicines, food and drink, pulse symptoms, hearing changes and how long each episode lasts.

Call emergency services for dizziness with facial drooping, one-sided weakness, trouble speaking, severe chest pain, severe breathlessness, fainting, a new severe headache, or inability to walk safely. Arrange prompt medical review for repeated episodes, new hearing loss, persistent vomiting, black stools, a racing or irregular heartbeat, or dizziness after starting or changing a medicine.

Ask whether your description suggests spinning or lightheadedness, whether blood pressure, blood count, glucose, heart rhythm or balance need checking, and whether any medicine could be contributing.