Recognising the Signs of Iron Deficiency: What Your Body Might Be Telling You

Iron deficiency is one of the most common nutritional issues worldwide, yet it often goes unnoticed until it begins to affect daily life. At its core, the condition arises when the body doesn’t have enough iron to produce haemoglobin – the protein in red blood cells responsible for carrying oxygen throughout the body.

Early signs can be easy to miss, but over time, low iron levels can lead to fatigue, reduced concentration, and a noticeable decline in overall wellbeing. Left untreated, the impact can become far more serious.

For anyone concerned about their energy levels, persistent tiredness, or unexplained symptoms, recognising the early indicators of iron deficiency is key. This article outlines the causes, symptoms, diagnostic methods, and treatment options available.

Why Is Iron Important?

Iron plays a fundamental role in producing haemoglobin, supporting oxygen transport, and maintaining healthy energy levels. It is also essential for optimal immune function, cognitive performance, and muscle metabolism. 

When iron levels fall, the body compensates by working harder to deliver oxygen, often resulting in fatigue and weakness. The importance of iron becomes more evident in those with chronic health conditions, high physical demands, or dietary restrictions. 

What Is Iron Deficiency?

Iron deficiency refers to a state in which the body’s iron stores fall below the required levels to maintain optimal function. 

Iron is essential for producing haemoglobin, the protein in red blood cells that carries oxygen throughout the body. When iron levels drop, the body initially compensates, but over time this shortfall can progress into iron-deficiency anaemia – a more advanced condition marked by a measurable reduction in red blood cells and haemoglobin concentration.

It is important to distinguish between low iron stores (also known as latent or non-anaemic iron deficiency) and iron-deficiency anaemia. In the early stages, iron may be depleted without yet affecting red blood cell production. This stage can still cause symptoms such as fatigue or reduced exercise tolerance, even in the absence of anaemia on blood tests. Iron-deficiency anaemia, by contrast, represents a later stage where the lack of iron impairs the body’s ability to produce enough healthy red blood cells, leading to more pronounced symptoms and potentially affecting organ function. 

Understanding this progression is vital, as intervention at the deficiency stage can often prevent the development of full anaemia.

What Causes Iron Deficiency Anaemia?

Iron deficiency anaemia can result from several underlying factors, such as:

Blood Loss

Chronic blood loss is the leading cause of iron deficiency in adults. This can result from heavy menstrual periods, gastrointestinal bleeding (due to ulcers, polyps, or bowel disorders), or frequent blood donations. In postmenopausal women and men, gastrointestinal bleeding is often the primary concern.

Insufficient Dietary Iron Intake

Diets low in iron-rich foods such as red meat, legumes, and leafy greens can result in low iron levels over time. Vegans, vegetarians, and individuals with unbalanced diets are particularly at risk, especially if they do not include iron-fortified foods or supplements.

An Inability to Properly Absorb Iron

Even if dietary intake is sufficient, conditions such as coeliac disease, inflammatory bowel disease (IBD), or bariatric surgery can impair iron absorption in the intestines. This makes it more difficult for the body to maintain adequate iron levels.

Pregnancy

During pregnancy, the demand for iron increases to support the developing foetus and placenta. Without adequate supplementation, pregnant individuals often become iron deficient, particularly in the second and third trimesters.

Regular Long-duration Physical Activity

High-intensity endurance training, particularly in athletes, can increase iron loss through sweating, gastrointestinal microbleeding, or haemolysis (destruction of red blood cells due to repetitive impact, such as in long-distance running).

Certain Medications

Long-term use of medications such as nonsteroidal anti-inflammatory drugs (NSAIDs), proton pump inhibitors (PPIs), or anticoagulants can contribute to gastrointestinal bleeding or reduce stomach acid, which impairs iron absorption.

What Are the Signs and Symptoms of Iron-Deficiency Anaemia?

Iron-deficiency anaemia often develops gradually, and its symptoms can be subtle or mistaken for everyday fatigue or stress. However, recognising the early signs is essential for timely diagnosis and effective treatment.

Some of the most common signs and symptoms associated with iron-deficiency anaemia include:

1. Constant Fatigue and Weakness

Persistent tiredness, even after rest, is one of the most reported symptoms. This results from the body’s reduced capacity to carry oxygen. As the condition progresses, daily tasks may become increasingly difficult to complete without feeling physically drained.

2. Pale or Yellow Skin

A common early sign, paleness in the skin or inner eyelids reflects reduced haemoglobin levels. It is often more noticeable in the face, palms, or inside the lower eyelid. In some cases, the skin may appear slightly yellow due to related red blood cell breakdown.

3. Shortness of Breath

Iron deficiency can make physical activities exhausting, even those requiring minimal effort. Oxygen delivery is compromised, causing individuals to feel breathless. 

4. Cold Hands and Feet

Poor circulation due to anaemia often leads to feelings of coldness in extremities. The body prioritises vital organs, leaving fingers and toes cold. 

5. Brittle Nails or Hair Loss

Thinning hair and fragile nails can occur as the body prioritises oxygen supply to essential tissues over peripheral structures like hair and nails. Nails may become spoon-shaped or develop ridges, while hair may shed more than usual.

6. Headaches

Frequent or persistent headaches may arise from insufficient oxygen reaching the brain, particularly during mental exertion or stress. These headaches are often accompanied by light-headedness or difficulty concentrating.

7. Rapid Heartbeat

The heart may beat irregularly or more rapidly as it compensates for decreased oxygen delivery. In severe cases, this can lead to heart complications. Some individuals may feel fluttering or pounding sensations in their chest.

8. Restless Legs Syndrome

A tingling or uncomfortable sensation in the legs, particularly at night, may indicate low iron levels. Restless Legs Syndrome is commonly associated with iron deficiency. 

9. Craving Ice or Non-food Items

Known as pica, the compulsion to chew on ice, chalk, or other non-nutritive items is a less understood but clinically significant sign of iron deficiency. This behaviour may be the body’s attempt to respond to underlying nutrient imbalances.

10. Swelling and Soreness of Your Tongue or Mouth

Glossitis (inflamed tongue) and mouth ulcers may develop. These signs are often accompanied by difficulty swallowing or a burning sensation. Cracks at the corners of the mouth are also frequently observed in individuals with iron deficiency.

Lesser-Known Symptoms of Iron Deficiency

Beyond the commonly recognised signs, iron deficiency can present with more nuanced symptoms that often go unnoticed. These subtle indicators can be easily mistaken for the effects of daily stress, poor sleep, or general fatigue, delaying proper diagnosis and treatment.

Cognitive changes are among the most overlooked effects. Individuals may experience difficulty concentrating, memory lapses, or a noticeable decline in mental clarity. Irritability and low mood are also frequently reported, suggesting a link between iron status and neurotransmitter function.

In physically active individuals, reduced endurance or slower recovery after exercise may be early clues. Even when overall haemoglobin levels remain within a normal range, low iron stores can impair muscle oxygenation and metabolic efficiency.

Children with iron deficiency may exhibit behavioural issues, attention deficits, or delayed growth and motor development. In adolescents, poor school performance or decreased interest in activities may be early signs.

Because these symptoms are often misattributed, it underscores the importance of medical evaluation, particularly blood tests, to confirm or rule out iron deficiency as the underlying cause.

Who Is Most at Risk?

Iron deficiency remains one of the most widespread nutritional deficiencies worldwide, with certain groups more vulnerable due to physiological, dietary, or medical factors. 

Populations at increased risk include:

• Women of childbearing age, due to monthly menstrual blood loss
• Pregnant individuals, as iron demands increase significantly during gestation
• People with chronic conditions, including kidney disease or cancer
• Those with gastrointestinal disorders, such as coeliac disease or inflammatory bowel disease, which impair iron absorption
• Vegetarians and vegans, especially if dietary intake lacks iron-rich or fortified foods
• Frequent blood donors, who may not replenish iron stores quickly enough between donations

For those in these risk categories, regular health checks can be essential in identifying iron deficiency before it progresses to anaemia.

How Iron Deficiency Is Diagnosed

Diagnosing iron deficiency requires a thorough and systematic approach, beginning with a detailed medical history and physical examination. Clinicians will typically explore dietary habits, menstrual history, chronic illnesses, and any symptoms suggestive of anaemia or blood loss.

A range of blood tests is used to confirm the diagnosis:

1. Complete blood count (CBC): This measures haemoglobin levels and the size and volume of red blood cells (mean corpuscular volume), both of which may be reduced in iron deficiency.
2. Serum ferritin: Ferritin reflects iron storage in the body and is usually the most sensitive marker for iron deficiency, although it can be falsely elevated in cases of inflammation.
3. Serum iron and transferrin saturation: These help assess how much iron is circulating in the bloodstream and how effectively it is being transported.
4. Total iron-binding capacity (TIBC): This test gives further insight into iron metabolism and can aid in differentiating types of anaemia.

If chronic gastrointestinal bleeding is suspected, further investigation through endoscopy or colonoscopy may be warranted to identify sources such as ulcers, polyps, or malignancies. For those who may not exhibit clear symptoms but belong to higher-risk groups, early diagnostic testing is recommended. 

Types of Anaemia

Understanding the specific types of anaemia is crucial for determining the appropriate treatment strategy. 

While iron-deficiency anaemia is the most common, other forms include:

• Vitamin Deficiency Anaemia: Caused by insufficient vitamin B12 or folate.
• Chronic Disease Anaemia: Associated with long-term illnesses.
• Aplastic Anaemia: A rare condition where the body stops producing enough blood cells.
• Hemolytic Anaemia: Occurs when red blood cells are destroyed faster than they can be made.
• Sickle Cell Anaemia: A genetic disorder that affects the shape and function of red blood cells.
• Thalassemia: An inherited blood disorder affecting haemoglobin production.

Effective Anaemia Treatments and Prevention Strategies

Effectively managing iron deficiency demands an individualised approach that both corrects existing deficiencies and reduces the likelihood of recurrence. Treatment strategies are determined by the severity of the deficiency and its underlying cause.

1. Lifestyle Tips

Preventing iron deficiency and maintaining healthy iron levels begin with lifestyle awareness and are sustained through consistent, balanced nutritional habits.

Start by including iron-rich foods in your regular meals. Lean red meats, organ meats (such as liver), and poultry offer heme iron, which is more readily absorbed by the body. For those following a plant-based diet, lentils, chickpeas, tofu, pumpkin seeds, spinach, and iron-fortified cereals provide non-heme iron, which can still be effective with proper dietary pairing. 

To improve the absorption of non-heme iron, it’s important to combine these foods with vitamin C-rich items, such as oranges, bell peppers, broccoli, or tomatoes. 

Avoid consuming tea, coffee, or calcium-rich foods or supplements around mealtimes, as tannins, polyphenols, and calcium can interfere with iron absorption. Try to leave at least one to two hours between these beverages and iron-rich meals.

2. Oral Iron Supplementation

Iron supplements are typically the first line of treatment when dietary measures alone are insufficient to correct iron deficiency. 

Oral iron tablets, such as ferrous sulphate or ferrous fumarate, are commonly prescribed for individuals with mild to moderate deficiency. They work by replenishing the body’s iron stores over time and are most effective when taken on an empty stomach, although this can increase the risk of side effects.

Gastrointestinal discomfort, including nausea, constipation, or dark stools, is a frequent complaint. To minimise these effects, patients are often advised to take the supplements with food, although this can slightly reduce absorption. 

Iron supplements typically need to be taken consistently for at least three to six months, even after symptoms improve, in order to restore both haemoglobin levels and iron stores. 

3. Intravenous Iron Infusions

For individuals who cannot tolerate oral iron or do not respond adequately to supplements, intravenous (IV) iron infusions provide an effective and medically-supervised alternative. 

This form of treatment delivers iron directly into the bloodstream, bypassing the digestive system entirely. It is especially beneficial for patients with severe iron deficiency, malabsorption syndromes, chronic inflammatory conditions, or ongoing blood loss that cannot be controlled through diet or tablets alone.

At the London Lauriston Clinic, intravenous iron infusions are administered in a safe, clinical environment by experienced healthcare professionals. Prior to treatment, a detailed consultation and blood work are carried out to determine suitability and iron requirements. The procedure typically takes between 15 to 60 minutes, depending on the type of iron preparation used, and most patients require just one or two sessions for significant improvement.

IV iron therapy often results in quicker restoration of iron levels and a more rapid resolution of symptoms such as fatigue and breathlessness, compared to oral supplements. It is a valuable option for those needing efficient correction of iron levels with minimal gastrointestinal side effects. 

Follow-up testing is essential to assess treatment response and ensure iron levels remain stable. Patients are therefore encouraged to schedule periodic assessments to support proactive management and maintain optimal iron balance.

When to See a Doctor

If you experience persistent fatigue, shortness of breath, dizziness, or other signs linked to iron deficiency anaemia, it is important to consult a healthcare professional. These symptoms may initially be mild but can gradually affect daily life and overall wellbeing.

Timely evaluation is essential, as untreated iron deficiency can progress to more serious complications, including severe anaemia, reduced immune function, impaired cognitive ability, and decreased physical endurance.

Turning to a private health clinic can offer faster access to diagnostics and more personalised care. At the London Lauriston Clinic, patients receive thorough assessments that go beyond routine testing, supporting early detection and tailored treatment.

Delaying medical attention can increase the risk of advanced health issues. If symptoms persist or intensify, seeking care promptly ensures the most effective intervention.

Frequently Asked Questions (FAQs) About Iron Deficiency

How do you know your iron is low?

Blood tests are the most accurate way, but symptoms like fatigue, pale skin, and shortness of breath may suggest it.

Can iron deficiency affect mental health?

Yes, it can lead to poor concentration, irritability, and even depression in some individuals.

Is it safe to take iron supplements without a test?

No. Excess iron can be harmful. Always consult a doctor before starting supplements.

What vitamins should you not take with iron supplements?

Avoid taking calcium and zinc at the same time as iron, as they compete for absorption.

What helps low iron immediately?

Iron supplements or, in urgent cases, intravenous iron infusions can quickly improve levels.

Is an iron infusion the best way to fix low iron levels?

For severe or resistant cases, yes. Intravenous iron infusions offer faster and more effective correction.

How long does it take to raise iron levels?

With oral supplements, it may take several months. Infusions can show improvement in weeks.

Conclusion

Iron deficiency is common, often overlooked, but highly manageable when addressed early. Many people live with symptoms for months, sometimes years, without realising that fatigue, shortness of breath, or brain fog may be linked to low iron levels.

Timely diagnosis and the right treatment plan can make a profound difference. Restoring iron levels not only improves physical energy but also supports cognitive function, mood, and overall wellbeing.

For those in London seeking discreet, expert-led care, the London Lauriston Clinic offers a personalised approach to diagnosing and managing iron deficiency. Whether through dietary guidance, supplements, or intravenous iron infusions, patients receive support tailored to their individual needs. 

With the right clinical insight and consistent follow-up, it’s entirely possible to regain strength and feel like yourself again.