The short answer
The most common signs are tiredness that sleep does not fix, brain fog, breathlessness on stairs, cold hands and feet, hair shedding and low mood. None of them proves low iron on its own. Together, they are a reason to ask for a ferritin test.
The ten signs
| Sign | What it can feel like |
|---|---|
| Tiredness | Drained rather than sleepy, even after a full night |
| Brain fog | Rereading lines, losing words halfway through a sentence |
| Breathless on stairs | A racing heart on a climb that used to be easy |
| Cold hands and feet | Cold when everyone else is warm |
| Hair shedding | More hair in the brush and the shower |
| Brittle nails, dry skin | Nails that split and peel |
| Seeing black when you stand | A head rush or dizziness on standing up |
| Slow recovery | Heavy legs and training that stalls |
| Hard mornings | Hard to wake, even after enough sleep |
| Low mood, short fuse | Less patience and drive, for no clear reason |
Iron carries oxygen in your red cells and helps make energy inside every cell. It also helps make dopamine, which runs motivation, and thyroid hormone, which sets your pace. So low iron rarely shows as one clear symptom. It shows as a slow fade that is easy to blame on work, sleep or age.
Restless legs at night, an urge to move your legs as you fall asleep, is also linked to low iron. Mention it to your doctor.
What to do with the list
- 1Tick the signs that are true for you, and note since when.
- 2Ask for a blood test that includes ferritin, not only haemoglobin. See what to ask for.
- 3Bring your period history: heavy periods are the most common reason women run low. Estimate yours with the period iron calculator.
Chest pain, fainting, a racing heart or breathlessness at rest need urgent care, not a blood test next week.
A real page from The Iron GuideThe whole guide on one page: ten rules that work together.See more pagesQuestions
Can you have low iron symptoms with normal haemoglobin?
Yes. Stores fall before haemoglobin does, and many women notice symptoms in that stage. See low ferritin with normal haemoglobin.
How quickly do symptoms improve?
Often within weeks once iron starts coming in, while stores take months to rebuild. See how long it takes.
Sources
- 1.World Health Organization. Anaemia, fact sheet
- 2.NIH Office of Dietary Supplements. Iron: fact sheet for health professionals
- 3.The Iron Guide, part 1: Why iron
This page has not been reviewed by a clinician yet. Read it as general education, and take your own results to your doctor.
Educational, not medical advice. ferritin.ai does not diagnose or treat any condition, and it never sets a dose. Talk to your doctor about your own results.