What should you know about altitude dizziness?

Sit or lie somewhere protected from falls, tell a companion and rest. Do not climb, drive or walk near an edge while unsteady. Worsening dizziness, inability to walk straight, confusion or breathlessness at rest requires descent and urgent help.

Dizziness can mean lightheadedness, a feeling of impending faint, imbalance or true spinning. At elevation, lightheadedness may occur with rapid breathing, exertion, inadequate fluid intake or an altitude-related illness. Spinning that is triggered by head movement can instead suggest an inner-ear problem.

Record what you felt and what happened just before it began. Food intake, heat exposure, fluid loss and medicines can matter. Anaemia, low blood glucose and an irregular heartbeat can also present with dizziness, so symptoms should not automatically be assigned to altitude if the pattern is unusual or persists after descent.

Stop exertion, sit down and rise only with support once steady. Drink according to thirst and have a snack if you have not eaten, provided you are awake and can swallow safely. Remain at the same elevation while symptoms are present.

If rest does not bring clear improvement, descend with a companion rather than continuing the route. Avoid alcohol and sedating medicines, which can cloud the assessment. Anyone who monitors blood glucose for diabetes should follow their personal plan when low glucose is suspected.

Seek emergency help for fainting, confusion, inability to coordinate steps, one-sided weakness, facial droop, trouble speaking, seizure, severe headache, chest pain, breathing difficulty at rest or repeated vomiting. Begin a safe, assisted descent when altitude illness is possible.

Medical review is also appropriate when dizziness keeps returning, continues at lower elevation, follows a new medicine, or comes with palpitations, hearing loss or ear symptoms. The examination may include balance, neurological, heart rhythm and blood-pressure checks.

Explain whether the feeling was spinning, faintness or imbalance; when it appeared relative to ascent; and whether sitting, eating, drinking or descending changed it. Ask if your health conditions or medicines could contribute and how to modify a future itinerary.