Low iron can cause a mix of subtle and obvious symptoms, but the only way to know for sure is with blood tests ordered by a healthcare professional. Symptoms can overlap with many other conditions, so do not self-diagnose or start iron supplements without medical advice.
Common low-iron symptoms
- Ongoing tiredness or fatigue that does not improve with rest, often with feeling weak or “wiped out”.
- Shortness of breath, faster heartbeat, or feeling lightheaded with usual activities or when standing up.
- Feeling cold more than others, headaches, and trouble concentrating can also be related to low iron.
Physical signs to watch for
- Pale skin, inner eyelids, or gums compared with your usual color.
- Brittle or spoon-shaped nails, hair loss or thinning, and cracks at the corners of the mouth.
- Restless legs, strange cravings to eat non-food items like ice or clay (pica), or frequent headaches may appear in some people.
Who is at higher risk
- People who menstruate heavily, are pregnant, or recently postpartum have higher risk of low iron.
- Those with diets low in iron (very low meat intake, poorly planned vegetarian/vegan diets) or with gut conditions affecting absorption (such as celiac or inflammatory bowel disease) are also at risk.
- Frequent blood donors, people with past stomach or bowel surgery, or with chronic bleeding (for example from the gut) should be especially cautious.
How doctors check your iron
- A basic test is a complete blood count (CBC), which looks at hemoglobin and red blood cells to check for anemia.
- More specific tests measure ferritin (iron stores), serum iron, transferrin saturation, and related markers to confirm low iron or iron-deficiency anemia.
- Sometimes a quick finger-prick hemoglobin test is used as a screening tool (for example at blood donation), but abnormal results usually need full lab tests to find the cause.
When to seek care and what to avoid
- See a doctor promptly if fatigue, breathlessness, chest discomfort, dizziness, or paleness are new, getting worse, or affecting daily life.
- Ask specifically for an evaluation of iron status (including ferritin), and mention any heavy periods, gut symptoms, or medications like NSAIDs that can cause bleeding.
- Avoid starting iron pills on your own for long periods, because too much iron can be harmful and may mask serious causes of blood loss; treatment dose and duration should be guided by lab results and a clinician.