What is Anaemia?
Anaemia affects half a billion women 15–49 years of age and 269 million children 6–59 months of age worldwide. In Singapore, it’s especially common among women. It happens when your body doesn’t produce enough healthy red blood cells, which contain a key protein called haemoglobin. Haemoglobin’s job is to carry oxygen from your lungs to the rest of your body.
Without enough oxygen, you may start feeling tired, dizzy, or even breathless. Anaemia may come on suddenly (acute) or develop gradually over time (chronic), and it can sometimes be a sign of a more serious underlying condition.
Among the different types of anaemia, iron deficiency anaemia is the most common—and fortunately, it's also one of the most treatable.
The most common causes of anaemia include:
- Insufficient red blood cells or haemoglobin production (iron deficiency anaemia, thalassemia, chronic infections, bone marrow and stem cell problems, and excessive alcohol intake)
- Increased red blood cell destruction or breakdown (sickle cell anaemia, an enlarged spleen, advanced liver or kidney disease, severe burns, and various haemoglobin disorders)
- Blood loss (post-surgery, certain gastrointestinal conditions like ulcers, haemorrhoids, and cancer, and medications such as NSAIDs)
What is Iron Deficiency Anaemia?
Iron deficiency anaemia is the most common cause of anaemia worldwide. It is caused by insufficient iron stores in the body, leading to the inadequate synthesis of haemoglobin.
Causes of iron deficiency anaemia include:
- Increased blood loss — This can occur as a result of menstruation (especially if the woman has heavy periods) or chronic blood loss due to medical conditions such as ulcers, tumours, polyps, and haemorrhoids.
- Low dietary intake of iron — Picky eaters/children, vegetarians, or people living in less developed countries are at higher risk.
- Iron malabsorption — Those who have digestive conditions like coeliac disease or have undergone any surgical procedures like a gastrectomy (removal of all or part of the stomach) may not be able to absorb sufficient iron from digested food.
- Pregnancy — During pregnancy, the volume of blood increases, and so does the amount of iron. The foetus also uses the mother’s iron supply to synthesise its own haemoglobin. Therefore, if the pregnant woman does not get enough iron or have sufficient iron stores, they can go on to develop iron deficiency anaemia.
Who is at risk of developing Iron Deficiency Anaemia?
Some groups are at a higher risk of developing iron deficiency anaemia:
- Women, especially those with heavy or frequent menstruation or pregnant women not on iron supplementation
- Children who happen to be picky eaters and are not willing to eat iron-rich foods such as green leafy vegetables, meat, and eggs
- Vegetarians may be at a higher risk, depending on the type and quantity of vegetables they consume
- Frequent blood donors, since blood donation requires the body to synthesise more red blood cells to replace what was donated
What are the Symptoms of Iron Deficiency Anaemia?
Iron deficiency anaemia can range in severity from patients being completely asymptomatic to having concerning symptoms, such as chest pain.
Common signs and symptoms of iron deficiency anaemia include:
- Weakness
- Fatigue
- Decreased ability to concentrate
- Noticeably pale skin, lips, and eyelids
- Giddiness or lightheadedness
- Decreased ability to exercise
- Headaches
In more severe cases, you may even experience:
- Chest pain, shortness of breath, increased heart rate
- Painful, red, and swollen tongue
- Brittle nails
- Pica (eating disorder) — cravings for ice, paper, soil, or other non-nutritious substances
Can “anaemia tongue” Point to Iron Deficiency Anaemia?
Anaemia tongue or glossitis is a prominent symptom of iron deficiency anaemia and is characterised by the following:
- Painful, tender and swollen tongue
- Reddish tongue with or without white patches
- Difficulty in speaking, chewing or swallowing
- Smooth appearance of the tongue due to loss of tongue papillae (the small bumps visible on a normal tongue)
How is Iron Deficiency Anaemia Diagnosed?
Iron deficiency anaemia is diagnosed by carrying out a number of blood tests, including a full blood count (FBC) and iron panel. The full blood count, also known as complete blood count (CBC) will measure various cellular components of your blood, such as red blood cells, white blood cells, platelets, haemoglobin, and haematocrit.
If you have iron deficiency anaemia, your blood test results will indicate a low level of iron with a low red blood cell count, and your red blood cells will be smaller and paler than normal. Your blood tests may also show the following:
- Low haematocrit ( percentage of red blood cells)
- Low ferritin (amount of protein that stores blood)
- Low mean cellular volume (average size and volume of red blood cells)
- Low iron saturation (amount of iron in the blood)
- High TIBC (total iron-binding capacity)
- Other Testing Methods for Iron Deficiency Anaemia
Additionally, further tests may be done to identify an underlying cause, such as bleeding from various sites, tumours or ulcers, and they include the following:
An endoscopy may be done. It involves inserting a flexible, thin tube down one’s throat, with a camera attached to the end, enabling direct visualisation of the appearance of your upper gastrointestinal tract (including the stomach & duodenum) and sampling of your tissue if required. Similarly, a colonoscopy may be offered. It involves the insertion of a flexible tube with a camera into the rectum and guided upwards into the colon. Any ulcers, bleeding, or abnormal masses suggestive of an underlying cause can be readily identified.
Endoscopy: This involves inserting a flexible, thin tube down your throat, with a camera attached at one end, enabling direct visualisation of the insides of the upper gastrointestinal tract (including the stomach and duodenum). A tissue sample may also be obtained if needed. Some Gastroenterologists may prefer using an endoscopic ultrasound over the conventional endoscopy because it can enhance the visualisation of the insides of the gastrointestinal tract and its surrounding structures.
Colonoscopy: This involves the insertion of a flexible tube with a camera at one end into the rectum and guided upwards into the colon. Any ulcers, bleeding, or abnormal masses suggestive of an underlying cause can be easily identified through this modality. If you’re looking to book an appointment for a colonoscopy in Singapore, our dedicated team at Alpha Digestive and Liver Centre is ready to assist—contact us today.
Gastroscopy: A gastroscopy is used to check inside your throat, food pipe (oesophagus) and stomach for underlying conditions causing iron deficiency, such as peptic ulcers, bowel polyps and/or certain cancers. Our team at Alpha Digestive and Liver Centre provides services for gastroscopy in Singapore, ensuring that you receive tailored care and treatment solutions.
Apart from symptoms of iron deficiency anaemia, doctors will also need to know about the kind of medications or supplements you are taking because the iron supplements that are prescribed for the treatment of iron deficiency anaemia can decrease the efficacy of some of your medications.
How Can I Check My Iron Levels at Home?
Although self-diagnosing is not recommended, the 'anaemia eyes test' can serve as a helpful self-check to indicate whether you should see a doctor for proper diagnosis and treatment of iron deficiency.
For this test, all you will require is a mirror. Simply pull your lower eyelids down so that the inner layer can be seen in the mirror. In a non-anaemic person, it should be pinkish red, but if you have anaemia, it may appear pale pink or yellowish-white.
In addition to the anaemia eyes test, there are various test kits that allow you to do it yourself at home.
There are many brands on the market, but in general, they all involve obtaining a small sample of your blood (using a small lancet included in the kit) and placing it into the test cassette. It is rather similar to checking one’s own blood sugar in diabetic patients, and the cassette resembles COVID self-test kits.
The results of the test should always be interpreted under the guidance of a doctor.
How is Iron Deficiency Anaemia Treated: Iron Deficiency Treatments
The treatment of iron deficiency anaemia involves replenishing the iron stores in the body as well as identifying and treating the underlying cause if necessary.
Iron is usually provided in the form of a tablet or occasionally intravenously (IV). Iron may also be given in liquid form for infants and children. The following approaches can help maximise the absorption of iron:
- Take your iron supplements on an empty stomach. But if it causes stomach aches, you can take it with your meal.
- Take iron in combination with Vitamin C or Vitamin C-containing food/drinks, as it increases iron absorption.
- Do not take iron at the same time as antacid medications, as they decrease iron absorption. If you require antacids, make sure to take them two hours before or four hours after you take the antacid.
Additionally, eating iron-rich foods such as meat, eggs, and leafy green vegetables (e.g., kale and spinach) can help boost your body’s iron stores. For children who may be picky eaters, there are special iron-fortified cereals available as well.
Depending on the underlying cause of iron deficiency anaemia, management may range from medications to reduce heavy menses to the treatment of any sites of bleeding or ulceration in the gastrointestinal tract, etc.
How Long Does it Take for the Iron Supplements to Work?
Although oral supplements typically start to work in about three to seven days, it generally takes around two to three weeks for the symptoms of iron deficiency anaemia to improve. Your iron stores will usually be replenished after three months of iron supplementation. Supplementation may also be continued for a few months to ensure iron deficiency anaemia does not recur.
Constipation and greyish-black stools are the most common side effects associated with iron supplementation, but constipation can be managed with laxatives. Overall, the benefits of iron supplementation outweigh the side effects, and you should continue taking them until the doctor has confirmed that your iron stores have been replenished.
Is Iron Deficiency Anaemia Permanent?
No, not necessarily, but this will depend on the treatment of the causal factor. In easily treatable causes like heavy menstrual bleeding or dietary shortages, treating the root cause will most likely cure the anaemia. However, in causes related to chronic blood loss from various sites in the body, the resolution of iron deficiency anaemia largely depends on how effectively the cause can be addressed.
What happens if Iron Deficiency Anaemia is Not Treated?
If left untreated, iron deficiency anaemia can have a significant impact on your health. A low blood count can put you at increased risk of heart attacks, tachycardia (rapid heart rate of more than 100 beats per minute) and a decrease in your ability to exercise normally. Additionally, low iron decreases your immunity and increases your risk of getting infections.
In pregnancy, severe iron deficiency anaemia increases the risk of a premature baby (born before 36 weeks). It is also associated with postpartum depression in the mother.
Summary
In conclusion, iron deficiency anaemia is a very common cause of anaemia and may have an immense impact on your health if left untreated. Fortunately, it is treatable with iron deficiency treatments: a combination of supplements and management of the underlying cause(s).
Visit Alpha Digestive & Liver Centre
If you have any of the iron deficiency symptoms mentioned above or feel you may be in the high-risk group, do reach out to our team at Alpha Digestive & Liver Centre to schedule an appointment with a trusted Consultant Gastroenterologists, Dr Benjamin Yip.
Not only is Dr Yip skilled in Gastroenterology, but he is also a Hepatologist. He can provide effective medical guidance on anaemia management, especially with regards to advanced liver disease, which can be a potential cause of anaemia.
Frequently Asked Questions
Iron deficiency can be caused by a combination of the following:
The common signs present in iron deficiency are as follows:
If you are experiencing any of these symptoms, please book a consultation at Alpha Digestive and Liver Centre.
To diagnose if you have iron deficiency, a doctor may run several tests to assess red blood cell size and colour, haematocrit, haemoglobin, and ferritin. In some cases, further procedures such as an endoscopy, colonoscopy, or ultrasound may be recommended.
When routine blood tests show iron deficiency anaemia—and especially if there’s no obvious cause such as heavy menstruation or pregnancy—your doctor may refer you to a Gastroenterologist to investigate possible internal bleeding or absorption issues in the digestive tract.
This is because many causes of iron deficiency are linked to conditions in the stomach or intestines, such as:
These procedures help your gastroenterologist look inside your digestive tract to check for any sources of bleeding, inflammation, or abnormal growths that might be causing blood loss or poor iron absorption:
These tests are generally safe, outpatient-based, and crucial in helping identify silent causes of iron deficiency anaemia, especially if other symptoms like changes in bowel habits, weight loss, or unexplained fatigue are also present.
A diet rich in iron can help combat iron deficiency. Foods like meat, eggs, leafy greens, and iron-fortified products are commonly recommended for those with low iron levels.
Iron deficiency treatments include increasing iron intake through diet (such as red meat, leafy greens, and legumes) and iron supplements, often alongside vitamin C to boost absorption. It’s essential to identify and manage underlying issues such as heavy bleeding or poor nutrient absorption. Be sure to consult a healthcare professional for diagnosis and appropriate treatment.
References
- Mayo Foundation for Medical Education and Research. (n.d.). Iron deficiency anemia. Mayo Clinic. https://www.mayoclinic.org/diseases-conditions/iron-deficiency-anemia/symptoms-causes/syc-20355034
- Cafasso J. Iron-deficiency anemia: Symptoms, causes, and more. Healthline. February 6, 2023. Accessed July 21, 2025. https://www.healthline.com/health/iron-deficiency-anemia.
- Iron-deficiency anemia. Hematology.org. Accessed July 21, 2025. https://www.hematology.org/education/patients/anemia/iron-deficiency.
- Iron-deficiency anemia. National Heart Lung and Blood Institute. Accessed July 21, 2025. https://www.nhlbi.nih.gov/health/anemia/iron-deficiency-anemia.
- NHS choices. Accessed July 21, 2025. https://www.nhs.uk/conditions/iron-deficiency-anaemia/.
- Iron-deficiency anemia. Hematology.org. Accessed July 21, 2025. https://www.hematology.org/education/patients/anemia/iron-deficiency.
- Iron-deficiency anemia could be the reason you’re so tired. Cleveland Clinic. June 2, 2025. Accessed July 21, 2025. https://my.clevelandclinic.org/health/diseases/22824-iron-deficiency-anemia.
