What are the symptoms of anaemia?

Anaemia means the blood cannot carry oxygen as effectively as usual, often because haemoglobin or red blood cells are low. The body may respond with low energy, weakness, headaches, poor concentration, daytime sleepiness, or breathlessness during activity. Some people notice a fast or pounding heartbeat, cold hands and feet, or reduced tolerance of cold. Symptoms can develop gradually, so they may be mistaken for stress, poor sleep, or being unfit. Vitamin B12 deficiency can cause anaemia and may also affect sensation or balance.

Arrange a clinical review if symptoms are persistent, worsening, or affecting work, exercise, or daily tasks. A clinician may ask about diet, menstrual or other bleeding, digestive symptoms, medicines, and family history, then use blood tests to identify the type and possible cause. Do not start iron or high-dose vitamin treatment without advice, because the correct treatment depends on the cause and excess supplements can be harmful. Keep a record of bleeding, palpitations, dizziness, and changes in stamina.

Seek urgent care for severe shortness of breath at rest, fainting, chest discomfort, confusion, a very fast or irregular heartbeat, or bleeding that does not stop. Prompt assessment is also needed for black stools, vomiting blood, or rapidly worsening weakness. These symptoms can have causes requiring immediate treatment and should not be attributed to anaemia without assessment.

Which blood tests will show whether I have anaemia and what type it is? Could blood loss, nutrition, inflammation, or vitamin B12 deficiency be involved? When should symptoms improve after treatment, and which changes should prompt earlier review?