Fatigue and feeling light-headed

Light-headedness can feel like faintness, weakness, or unsteadiness, and differs from the spinning sensation of vertigo. Standing quickly, heat, sweating, vomiting, diarrhoea, missed meals, or low fluid intake can reduce circulation to the brain briefly. Anaemia may cause tiredness with paleness, headaches, or breathlessness. Infection, low blood sugar, heart rhythm problems, alcohol, and medicines that lower blood pressure are other possibilities. The symptom pattern matters more than one isolated episode.

Sit or lie down immediately, raise your legs if comfortable, and avoid driving, heights, or machinery until steady. Sip fluids and eat if you may have missed a meal and can swallow safely. Rise slowly and keep a record of triggers, position, duration, palpitations, bleeding, and medicines. Do not stop prescribed treatment without advice. Arrange a clinical review if episodes recur or fatigue does not settle.

Get emergency help for fainting with injury, chest pain, severe breathlessness, a fast or irregular heartbeat, new weakness or numbness, trouble speaking, confusion, severe headache, or black or bloody stools. Seek prompt care for repeated near-fainting, ongoing vomiting, heavy bleeding, fever, or symptoms that occur during exertion. Someone who remains unconscious or is not breathing normally needs emergency services immediately.

Could dehydration, anaemia, blood pressure, heart rhythm, blood sugar, or a medicine explain this? Should I have blood pressure measurements lying and standing, an examination, or blood tests? What should I do if it happens at work or while driving? Which symptoms require emergency help?