What should you know about pre syncope causes?

Presyncope can feel like light-headedness, weakness, blurred or narrowing vision, nausea, sweating or hearing changes while you remain conscious. It may follow standing quickly, prolonged standing, heat, pain, emotional stress or not eating and drinking enough. A drop in blood flow to the brain can produce the warning symptoms.

Anaemia may reduce oxygen delivery, while atrial fibrillation and other rhythm problems can affect the heart's output. Dehydration and hypoglycaemia are also possible contributors. A single episode can have a simple trigger, but repeated or unexplained episodes need assessment.

Lie down promptly with your legs raised if possible, or sit with your head lowered. Loosen tight clothing, move away from heat and avoid walking until the feeling passes. If you are fully alert and able to swallow, sip water; if low blood sugar is possible, follow your diabetes treatment plan. Record what you were doing, your position, food and fluids, medicines and symptoms.

Call emergency services for chest pain, severe breathlessness, a racing or irregular heartbeat, new weakness, trouble speaking, seizure-like movements, serious injury or fainting during exercise. Seek prompt medical review if episodes recur, occur without warning, happen while lying down, or affect someone with known heart disease. Do not drive while unexplained episodes continue.

Could my medicines, blood pressure, blood count, glucose or heart rhythm explain this? Do I need an ECG or other tests? What should I do if the warning feeling returns?