What should you know about sudden pale skin?

Paleness can happen when blood vessels narrow during fear, pain, cold, nausea, or a near-faint. It may also reflect reduced blood flow or blood loss. Anaemia and iron deficiency anaemia often present with pallor alongside tiredness, breathlessness on exertion, dizziness, headaches, or a fast heartbeat. Vitamin B12 deficiency can add numbness or balance problems. Sickle cell disease and thalassaemia are inherited blood conditions with their own patterns of anaemia and other symptoms. Skin tone, lighting, and natural complexion can make colour changes difficult to judge, so check the lips, inside of the lower eyelid, and palms as well as the face.

If you feel faint, lie flat with your legs raised when safe, loosen tight clothing, and get fresh air. Do not stand suddenly or drive while dizzy. Look for bleeding, black stools, vomiting blood, severe pain, breathing difficulty, or a cold clammy feeling. Note when the colour change began, whether it is widespread or limited to one limb, and any recent illness, heavy menstrual bleeding, diet change, or new medicine. Do not start iron supplementation without checking whether iron deficiency is present and discussing a suitable product with a clinician.

Call emergency services for fainting that does not resolve, severe breathlessness, chest pain, confusion, heavy bleeding, blue lips, or sudden pallor with a cold painful limb. Seek prompt care for repeated near-fainting, a racing heartbeat, marked weakness, new neurological symptoms, or possible internal bleeding. Arrange a medical review if pallor persists, keeps returning, or occurs with fatigue, reduced exercise tolerance, weight change, or unusual bleeding.

Could anaemia, blood loss, circulation, or a vitamin deficiency explain the change? Do I need a blood count or other tests? Should I change my diet or take iron? Which symptoms require urgent help?