What should you know about low iron fatigue?

Iron helps make haemoglobin inside red blood cells. When iron stores fall, fatigue may appear before anaemia develops; if anaemia develops, reduced oxygen delivery can make ordinary activity feel unusually demanding. People may describe low energy, reduced concentration, weakness, breathlessness on exertion, dizziness, or a faster heartbeat. These features overlap with dehydration, burnout, infection, chronic kidney disease, coeliac disease, and other causes, so fatigue alone cannot identify the cause.

A clinician may ask about diet, menstrual or other bleeding, digestive symptoms, long-term illness, and medicines. Blood tests can assess iron stores and blood counts, while the reason for low iron may need separate evaluation.

Arrange a primary-care appointment if tiredness persists, returns, or affects work, study, exercise, or daily tasks. Keep a note of bleeding, dietary changes, bowel symptoms, breathlessness, dizziness, and medicines or supplements. Do not start high-dose iron without advice: excess iron can be harmful, and treating the deficiency without finding its cause may delay useful care.

Eat a varied diet that includes iron-containing foods such as meat, beans, lentils, leafy greens, and fortified foods. A clinician can advise whether an iron supplement is appropriate, which form to use, and how follow-up blood tests should be timed. Seek assessment for possible anaemia rather than assuming every episode of tiredness is low iron.

Seek urgent medical help for severe or rapidly worsening breathlessness, chest pain, fainting, confusion, a racing heartbeat with marked weakness, or heavy bleeding. Arrange prompt assessment for black or bloody stools, repeated vomiting, unexplained weight loss, or fatigue that is steadily worsening. In children, pregnancy, older age, or known long-term illness, discuss persistent fatigue with a clinician sooner.

Could my symptoms fit low iron or anaemia, and which blood tests would clarify that? What could be causing low iron in my situation? Should I change my diet or take iron, and what side effects should I report? When should my symptoms and blood results be reviewed?