Iron Deficiency: Symptoms You Should Not Ignore
Iron Deficiency: Symptoms You Should Not Ignore
Feeling tired after a busy week is normal. Feeling persistently exhausted, breathless or aware of your heartbeat for no obvious reason is different.
Iron deficiency is a common cause of anaemia, and symptoms can develop gradually enough that people begin to treat them as normal. Iron is needed to make haemoglobin, the substance in red blood cells that helps carry oxygen around the body. When iron stores become too low, the body may eventually struggle to make enough healthy red blood cells.
Low iron is usually treatable, but it is also important to understand why the deficiency has developed rather than simply taking supplements indefinitely.
Quick Answer
Common symptoms of iron deficiency anaemia include persistent tiredness, low energy, shortness of breath, noticeable heartbeats, headaches and skin that appears paler than usual. Some people also develop hair loss, a sore tongue, restless legs, changes to their nails or cravings for non food substances such as ice.
These symptoms are not specific to iron deficiency, so they cannot confirm the condition on their own. A GP can arrange blood tests and, if iron deficiency is confirmed, consider what may be causing it.
Heavy periods and pregnancy are common causes. Blood loss from the stomach or bowel, difficulty absorbing iron and inadequate iron intake can also contribute.
What Is Iron Deficiency?
Iron is a mineral the body needs to produce healthy red blood cells.
These cells contain haemoglobin, which carries oxygen from the lungs to tissues around the body.
Iron deficiency develops when the body's available iron becomes too low.
If this progresses far enough to reduce haemoglobin or healthy red blood cells, it can result in iron deficiency anaemia.
The two terms are related, but they are not exactly the same. It is possible to have depleted iron stores before anaemia has fully developed. British Society of Gastroenterology guidance recommends confirming iron deficiency using appropriate iron studies, with serum ferritin being a particularly useful marker.
What Are the Most Common Symptoms of Iron Deficiency Anaemia?
Symptoms vary according to how low the haemoglobin is, how quickly the problem has developed and the individual person.
Some people have few noticeable symptoms.
Others gradually realise that everyday activities have become harder.
Persistent tiredness
Tiredness and lack of energy are among the most common symptoms.
This can feel different from simply needing an early night.
You may notice that you:
feel exhausted despite sleeping struggle with your normal routine have less energy for exercise become tired more quickly than usual need more rest during everyday activities
Tiredness has many possible causes, so it should not automatically be attributed to iron deficiency.
Shortness of breath
When haemoglobin is reduced, the blood cannot carry oxygen as effectively.
Some people therefore become more breathless than expected, particularly during physical activity.
You might notice that stairs, walking uphill or activities that were previously easy suddenly leave you unusually short of breath.
Noticeable heartbeats or palpitations
Iron deficiency anaemia can sometimes cause heart palpitations, where you become unusually aware of your heartbeat.
It may feel as though your heart is:
beating strongly beating quickly fluttering pounding
Palpitations have many potential causes and are not automatically due to low iron.
If palpitations are persistent, recurrent or accompanied by other symptoms, they should be medically assessed.
Pale skin
Some people with iron deficiency anaemia appear paler than usual.
This can sometimes be easier to notice on the face, inside the lower eyelids or around the nail beds, although skin tone makes this sign much more or less obvious between individuals.
Paleness alone is not a reliable way to diagnose anaemia.
Headaches
Headaches can occur with iron deficiency anaemia, although headaches are extremely common and have many other explanations.
If headaches are new, persistent or significantly different from what you normally experience, speak to a healthcare professional.
What Are the Less Obvious Signs of Iron Deficiency?
Iron deficiency anaemia can sometimes cause symptoms that people would not immediately associate with low iron.
These may include:
hair loss a sore or unusually smooth tongue altered taste itching tinnitus cracks or ulcers at the corners of the mouth difficulty swallowing spoon shaped nails restless legs syndrome
None of these symptoms proves that someone is iron deficient.
The important point is that iron deficiency can present in ways that go beyond simply feeling tired.
Why Can Low Iron Cause Restless Legs?
Restless legs syndrome involves an uncomfortable urge to move the legs, often becoming more noticeable when sitting or lying down and particularly in the evening or at night.
Iron deficiency is one recognised association.
If restless legs are persistent or interfering with sleep, mention them to your GP rather than assuming they are simply a sleep problem.
Why Would Someone Crave Ice?
A desire to eat substances that are not normally considered food is called pica.
The NHS lists cravings for items such as ice or paper among the less common symptoms of iron deficiency anaemia.
Someone repeatedly chewing or craving ice may not immediately connect this with iron levels.
Pica can have different causes, so it is worth mentioning to a healthcare professional.
Can Hair Loss Be Caused by Low Iron?
Hair loss is listed by the NHS as a possible symptom of iron deficiency anaemia.
However, hair loss is common and can occur for many reasons, including:
stress hormonal changes illness genetics thyroid problems nutritional deficiencies some medicines
It is therefore better to investigate persistent or unexplained hair loss rather than simply starting iron supplements.
What Causes Iron Deficiency?
There is no single cause.
In broad terms, iron deficiency usually develops because the body is:
losing iron not absorbing enough iron not receiving enough iron or needs more iron than usual
Finding the reason matters because replacing iron without addressing an ongoing cause may only provide a temporary solution.
Can Heavy Periods Cause Iron Deficiency?
Yes.
Heavy menstrual bleeding is a common cause of iron deficiency anaemia.
If periods are consistently very heavy, it is worth discussing this with your GP.
Signs that bleeding may be unusually heavy can include needing to change menstrual products very frequently, bleeding through clothing or bedding, passing large clots or periods significantly interfering with normal activities.
Heavy periods themselves can also have several causes, so they deserve assessment rather than simply assuming low iron is inevitable.
Is Iron Deficiency Common During Pregnancy?
Iron requirements increase during pregnancy, and iron deficiency anaemia can occur because more iron is needed to support the pregnancy and increased blood volume.
The NHS lists pregnancy as one of the common causes of iron deficiency anaemia.
If you are pregnant, follow advice from your midwife, GP or maternity team rather than starting high dose iron supplementation yourself.
Can Stomach or Bowel Problems Cause Low Iron?
Yes.
Chronic blood loss from the gastrointestinal tract can cause iron deficiency.
Possible causes include:
stomach ulcers inflammation affecting the bowel or oesophagus piles regular use of some medicines such as NSAIDs bowel or stomach cancer, although this is a less common cause overall
Iron deficiency can also occur when iron is not absorbed properly.
For example, British Society of Gastroenterology guidance identifies coeliac disease as an important possible cause and recommends screening for it in confirmed iron deficiency anaemia.
This is why unexplained iron deficiency, particularly in men and postmenopausal women, should not simply be treated with supplements without considering the underlying cause.
Can Ibuprofen or Aspirin Affect Iron Levels?
They can sometimes contribute indirectly.
Non steroidal anti inflammatory drugs, known as NSAIDs, include medicines such as ibuprofen and aspirin.
Long term or frequent use can sometimes cause irritation, ulcers or bleeding within the gastrointestinal tract, which may contribute to iron deficiency anaemia.
Do not stop prescribed medication without speaking to the healthcare professional responsible for your treatment.
Can Diet Cause Iron Deficiency?
Yes, although diet is only one possible explanation.
Good dietary sources of iron include:
meat beans chickpeas and other pulses nuts fortified breakfast cereals dark green leafy vegetables dried fruit such as apricots
People following restricted diets may need to pay closer attention to iron intake.
However, someone with confirmed iron deficiency should not automatically assume that their diet is the cause.
Blood loss or poor absorption may also need to be considered.
Does Tea or Coffee Affect Iron Absorption?
Tea and coffee can reduce the absorption of iron when consumed around the same time as iron rich food or iron tablets.
The NHS advises that large amounts of tea, coffee, milk and some foods containing high levels of phytic acid can make it harder for the body to absorb iron.
That does not mean everyone needs to stop drinking tea or coffee.
If you are being treated for iron deficiency, follow the specific advice given by your doctor or pharmacist about how and when to take your iron medicine.
How Is Iron Deficiency Diagnosed?
Symptoms alone are not enough.
If your GP suspects anaemia, they will usually arrange a full blood count, commonly shortened to FBC.
This measures different types of blood cells and can show whether haemoglobin and red blood cell measurements are abnormal.
Where iron deficiency needs to be confirmed, further iron studies may be used.
The British Society of Gastroenterology states that serum ferritin is the single most useful marker of iron deficiency anaemia, although other tests such as transferrin saturation can sometimes help where ferritin results may be misleading.
Your doctor may also consider additional tests depending on:
your age symptoms medical history menstrual history diet medicines whether there is any obvious source of blood loss What Is Ferritin?
Ferritin is a protein that stores iron.
A ferritin blood test can therefore help clinicians assess the body's iron stores.
Interpreting ferritin is not always as simple as saying low equals deficiency and normal equals no deficiency.
Certain illnesses and inflammation can affect ferritin levels, which is one reason doctors interpret results alongside other blood tests and the wider clinical picture. The British Society of Gastroenterology notes that other iron measurements can be helpful if a falsely normal ferritin is suspected.
Can You Have Low Iron Without Anaemia?
Yes.
Iron stores can become depleted before haemoglobin falls sufficiently for someone to meet the definition of anaemia.
This is sometimes referred to as iron deficiency without anaemia.
The clinical significance depends on the person, their results and the reason for the deficiency.
British Society of Gastroenterology guidance notes that the risk of gastrointestinal cancer in iron deficiency without anaemia is low, but the cause of iron deficiency still needs to be considered appropriately.
Should You Take Iron Tablets Just in Case?
Generally, no.
Iron supplements are useful when there is a genuine reason to take them, but they are not something everyone with tiredness should start automatically.
The Northern Ireland Formulary specifically states that treatment with an iron preparation should be justified by a demonstrable iron deficiency state and that serious underlying causes of anaemia should be excluded where appropriate.
Taking supplements without assessment could also delay investigation of another explanation for your symptoms.
If you think you may be iron deficient, speak to your GP rather than relying on symptoms alone.
How Is Iron Deficiency Anaemia Treated?
Treatment depends on both:
- Replacing the missing iron
and
- Treating or investigating the underlying cause
Iron tablets are commonly used.
The NHS advises that treatment may need to continue for several months and that repeat blood tests may be carried out to make sure iron levels and blood counts are returning towards normal.
Some people experience side effects from oral iron, including:
constipation diarrhoea stomach discomfort heartburn nausea darker stools
If side effects are difficult to tolerate, speak to your GP or pharmacist rather than simply stopping treatment.
Will Eating More Iron Rich Food Fix Low Iron?
Sometimes dietary changes can help, particularly where intake has been inadequate.
But food alone may not be enough to correct established iron deficiency anaemia.
If you have confirmed anaemia, follow the treatment recommended by your healthcare professional.
More importantly, diet will not solve iron deficiency caused by ongoing blood loss or an absorption problem.
That underlying issue still needs attention.
How Quickly Do Iron Levels Improve?
Recovery is not immediate.
The NHS advises that people taking ferrous sulphate may begin to feel better after around three to four weeks, although it can take longer for the medicine to have its full effect.
How quickly someone improves depends on:
how deficient they were the cause whether blood loss is continuing how well treatment is absorbed how consistently treatment is taken other health conditions
Do not use symptom improvement alone to decide whether treatment has worked.
Repeat blood tests may still be needed.
When Should You Speak to Your GP?
Speak to your GP if you have symptoms that could suggest iron deficiency anaemia, particularly if they are persistent, unexplained or worsening.
This includes:
unusual tiredness breathlessness recurring palpitations persistent headaches alongside other symptoms unexplained paleness unusual hair loss restless legs cravings for ice or other non food substances heavy periods unexplained changes in your ability to exercise or carry out normal activities
The NHS specifically recommends seeing a GP if you think you may have iron deficiency anaemia.
If symptoms such as breathlessness, chest discomfort, fainting or palpitations are sudden or severe, seek urgent medical advice rather than assuming they are caused by low iron.
What Should You Not Ignore?
Most symptoms associated with iron deficiency are not emergencies.
What matters is a persistent change from what is normal for you.
Do not ignore:
Tiredness that does not improve
Especially when it begins interfering with work, exercise or ordinary activities.
Unexplained breathlessness
Particularly if activities that were previously easy become noticeably difficult.
Recurrent heart palpitations
Especially when they are new or accompanied by breathlessness, dizziness or chest symptoms.
Heavy or prolonged bleeding
Repeated blood loss can gradually deplete iron stores.
Iron deficiency with no obvious explanation
This is particularly important because gastrointestinal blood loss can sometimes occur without obvious visible bleeding.
Symptoms that return after treatment
Recurrent iron deficiency may mean the cause is still present and needs further investigation.
What Support Is Available in Northern Ireland?
If you live in Northern Ireland and think you may have iron deficiency, your GP is usually the appropriate first point of contact.
They can assess your symptoms and arrange blood testing where clinically appropriate.
The Northern Ireland Formulary provides local prescribing guidance for treating confirmed iron deficiency anaemia and emphasises identifying an underlying cause rather than using iron treatment without evidence of deficiency.
nidirect also advises people experiencing symptoms of iron deficiency anaemia to speak to their GP for assessment and blood testing.
Looking After Your Health in Northern Ireland
Keltoi Wellness provides doctor led remote healthcare services for adults across Northern Ireland.
Some symptoms discussed in this article can overlap with other health issues, and unexplained tiredness should not automatically be assumed to be caused by iron deficiency.
Iron deficiency normally requires appropriate blood testing and consideration of the underlying cause.
If you experience persistent symptoms, your GP is usually the best place to start.
Keltoi provides the administrative and patient support element of its services. Clinical decisions within Keltoi services are made independently by the treating doctor.
The Bottom Line
Iron deficiency can be easy to miss because symptoms often develop gradually.
Persistent tiredness, breathlessness, palpitations, headaches and unusual paleness are among the main signs worth paying attention to. Less obvious symptoms can include restless legs, hair loss, tongue changes and cravings for ice or other non food substances.
But symptoms alone cannot diagnose iron deficiency.
A blood test can help establish whether anaemia or depleted iron stores are present, while further assessment may be needed to understand why.
If you think you may have iron deficiency, do not simply assume you need supplements. Speak to your GP and find out what is actually causing the problem.
Sources
NHS Iron deficiency anaemia Symptoms, causes, diagnosis, treatment and dietary advice.
NHS Vitamins and minerals: Iron UK guidance on the role of iron, recommended intake and dietary sources.
NHS Blood tests Information on full blood counts and the use of blood testing when investigating iron deficiency anaemia.
nidirect Iron deficiency anaemia Northern Ireland patient guidance on symptoms, diagnosis and when to contact a GP.
Northern Ireland Formulary 9.1.1 Iron deficiency anaemia Northern Ireland prescribing guidance and advice on confirming deficiency and investigating the underlying cause.
British Society of Gastroenterology Guidelines for the Management of Iron Deficiency Anaemia in Adults Guidance on diagnosis, iron studies, ferritin and investigation of underlying causes. The BSG page records the guideline as reviewed in 2026.
British Society of Gastroenterology and Association of Coloproctology of Great Britain and Ireland Guidelines on the role of FIT in the endoscopic investigation of iron deficiency anaemia, 2025 Current supplementary UK guidance on gastrointestinal investigation of iron deficiency anaemia.
NHS Common questions about ferrous sulfate Patient guidance on iron replacement treatment and expected timescales for improvement.