Anemia means your blood doesn't carry enough oxygen, usually because of low haemoglobin or red blood cells. The most common cause is iron deficiency, but vitamin B12, folate and chronic conditions also play a role.
Typical signs include fatigue, breathlessness, pale skin, dizziness and brittle nails. In children it can affect concentration and growth.
A complete blood count (CBC) is the first step, often followed by iron studies, ferritin and vitamin B12 to pinpoint the cause.
The good news: most forms of anemia are very treatable once the cause is identified — which is why testing, rather than guessing, is the right first move.