What should you know about sudden cold intolerance?

Cold intolerance means feeling unusually cold in situations that others find comfortable. New symptoms may follow weight change, reduced food intake, illness, or a change in medication. Hypothyroidism can cause cold sensitivity with tiredness, dry skin, constipation, slower thinking, or weight gain. Anaemia, including iron deficiency anaemia, may occur with low energy, breathlessness on exertion, paleness, headaches, or fast heartbeats. These symptoms overlap, so the feeling alone cannot identify the cause.

Keep warm with breathable layers, eat regular nourishing meals, and record when the cold feeling occurs. Note weight changes, menstrual or other bleeding, bowel changes, skin changes, tiredness, breathlessness, and medicines or supplements. Arrange a GP appointment if the change continues, affects daily activities, or comes with marked fatigue. A clinician may examine you and request blood tests before recommending treatment such as thyroid hormone replacement.

Seek urgent help for confusion, fainting, chest pain, severe breathlessness, blue lips, or a very low body temperature after cold exposure. Same-day assessment is sensible for heavy bleeding, black stools, rapidly worsening weakness, or a fast irregular heartbeat. Do not start iron or thyroid medicine based only on a symptom search; the wrong treatment can obscure the cause or cause harm.

Could my symptoms fit anaemia, iron deficiency, or hypothyroidism? Which blood tests are appropriate? Could a medicine, diet change, or bleeding explain the new cold sensitivity?