Iron-deficiency anemia is the most common type of anemia, which occurs when your body does not have enough of the mineral iron. Your body needs iron to produce a protein called hemoglobin, which is responsible for carrying oxygen to your body’s tissues. Your tissues and muscles need oxygen to function effectively. You can usually correct iron deficiency anemia with iron supplementation. Sometimes additional tests or treatments for iron deficiency anemia are necessary, especially if your doctor suspects that you’re bleeding internally. Iron deficiency causes approximately half of all anemia cases worldwide, and affects women more often than men.
Causes
Iron deficiency anemia is the most common form of anemia.
Red blood cells bring oxygen to the body’s tissues. Healthy red blood cells are made in your bone marrow. Red blood cells circulate through your body for 3 to 4 months. Parts of your body, such as your spleen, remove old blood cells.
Iron is a key part of red blood cells. Without iron, the blood cannot carry oxygen effectively. Your body normally gets iron through your diet. It also reuses iron from old red blood cells.
You get iron deficiency anemia when your body’s iron stores run low. This can occur because:
- You lose more blood cells and iron than your body can replace
- Your body does not do a good job of absorbing iron
- Your body is able to absorb iron, but you are not eating enough foods that contain iron
- Your body needs more iron than normal (such as if you are pregnant or breastfeeding)
Bleeding can cause iron loss. Common causes of bleeding are:
- Heavy, long, or frequent menstrual periods
- Cancer in the esophagus, stomach, small bowel, or colon
- Esophageal varices, usually from cirrhosis
- The use of aspirin, ibuprofen, or arthritis medicines for a long time, which can cause gastrointestinal bleeding
- Peptic ulcer disease
The body may not absorb enough iron in your diet due to:
- Celiac disease
- Crohn disease
- Gastric bypass surgery
- Taking too many antacids that contain calcium
You may not get enough iron in your diet if:
- You are a strict vegetarian
- You are an older adult and do not eat a full diet
Symptoms
Symptoms of iron-deficiency anemia can be very mild at first, and may go completely unnoticed. In fact, most people do not realize they have mild anemia until it is identified in a routine blood test.
Symptoms of moderate to severe iron-deficiency anemia include:
- general fatigue
- weakness
- pale skin
- shortness of breath
- dizziness
- strange cravings for non-food items, such as dirt, ice, and clay
- tingling or a crawling feeling in the legs
- swelling or soreness in the tongue
- cold hands and feet
- fast or irregular heartbeat
- brittle nails
- headaches
Diagnosis
If you experience symptoms of iron deficiency anemia, see your GP. A simple blood test can usually confirm the diagnosis.
Your GP may also carry out a physical examination and ask you a number of questions, to determine the cause of your anemia.
Blood Test
To diagnose iron deficiency anemia, a blood sample is taken from a vein in your arm and a full blood count is made. This means all the different types of blood cells in the sample will be measured.
If you have anemia:
- your levels of haemoglobin (a substance that transports oxygen) will be lower than normal
- you will have fewer red blood cells (which contain hemoglobin) than normal
- your red blood cells may be smaller and paler than usual
Your GP may also test for a substance called ferritin a protein that stores iron. If your ferritin levels are low, there is not much iron stored in your body and you may have iron deficiency anemia.
Vitamin B12 and Folate Deficiency
If your GP thinks your anemia may be due to a vitamin B12 and folate deficiency, the levels of these substances may be tested. Folate works with vitamin B12 to help your body produce red blood cells.
This type of anemia is more common in people who are over 75 years old.
Finding the Cause
To determine the underlying cause of your anaemia, your GP may ask questions about your lifestyle and medical history. For example, you may be asked about:
- your diet – to see what you typically eat and whether this includes any iron-rich foods
- any medicines that you take – to see if you have been regularly taking a type of medicine that can cause gastrointestinal bleeding (bleeding from the stomach and intestines), such as ibuprofen or aspirin
- your menstrual pattern – if you’re a woman, your GP may ask if you have been experiencing particularly heavy periods
- your family history – you will be asked if your immediate family has anemia or a history of gastrointestinal bleeding or blood disorders
- blood donation – your GP may ask if you regularly donate blood
- other medical conditions – your GP may ask if you have recently had another illness or experienced other symptoms, such as weight loss
Iron deficiency anaemia is common during pregnancy. If you are pregnant, your GP will usually only look for an alternative cause if a blood test has shown a particularly low haemoglobin level, or if your symptoms or medical history suggest your anaemia may be due to something else.
Physical Examination
A physical examination will usually only be needed if the cause has not been found through your medical history and symptoms.
In these cases, your GP may:
- examine your abdomen (stomach) to check for any physical signs of gastrointestinal bleeding
- look for signs of heart failure (when your heart is not pumping blood around your body very efficiently), such as swollen ankles, as heart failure can have some similar symptoms to iron deficiency anaemia.
Two other possible types of physical examination you may have are explained below:
Rectal Examination
A rectal examination is usually only needed if you are bleeding from your bottom. This is a common procedure that can help your GP find out if there is something in your gastrointestinal tract that is causing bleeding. Your GP will insert a gloved, lubricated finger into your bottom so they can feel any abnormalities.
A rectal examination is not something to be embarrassed about, as it is a procedure your GP will be used to doing. It should not cause great pain or discomfort, and you will only feel a slight feeling, as if your bowels are moving.
Pelvic Examination
Women may have a pelvic examination if their GP suspects heavy menstrual bleeding (menorrhagia) may be the cause of their anaemia.
During a pelvic examination, your GP will examine your vulva and labia (external sex organs) for signs of bleeding or infection. They may also examine you internally. This will involve your GP inserting gloved, lubricated fingers into your vagina to feel whether your uterus (womb) is tender or enlarged.
A pelvic examination will not be done without your consent, and you can choose to have someone with you.
Referral to a Specialist
In some cases, your GP may refer you to a gastroenterologist (a specialist in treating digestive conditions), who can carry out a more thorough examination.
For example, you may be referred to a gastroenterologist if your GP can’t identify a cause and you have a particularly low haemoglobin level, or if your GP thinks there is a possibility your symptoms could be caused by stomach or colon cancer (although these are unlikely to be the cause).
If you are a woman with heavy periods, you may be referred to a gynaecologist if you don’t respond to treatment with iron supplements.
Treatment
Iron Supplements
Iron tablets can help restore iron levels in your body. If possible, you should take the iron tablets on an empty stomach to improve absorption. If they upset your stomach, they can be taken with meals. You may need to take the supplements for several months. Iron supplements may cause constipation or stools that are black in color.
Diet
Diets high in red meat, dark leafy vegetables, dried fruits and nuts, and iron-fortified cereals can help treat or prevent iron deficiency. Additionally, vitamin C helps your body absorb iron. If you are taking iron tablets, a doctor might suggest taking the tablets along with a source of vitamin C, like a glass of orange juice or citrus fruit.
Treating the Underlying Cause of Bleeding
Iron supplements will not help if the deficiency is caused by excess bleeding. Oral contraceptives (birth control pills) might be prescribed to women who experience heavy periods to reduce the amount of menstrual bleeding each month.
In the most severe cases, a blood transfusion can replace iron and blood loss quickly.
Prevention
A balanced diet should include enough iron. Red meat, liver, and egg yolks are high sources of iron. Flour, bread, and some cereals are fortified with iron. If advised by your doctor, take iron supplements if you are not getting enough iron in your diet.
Prognosis
Iron deficiency anemia is an easily treated disorder with an excellent outcome; however, it may be caused by an underlying condition with a poor prognosis, such as neoplasia. Similarly, the prognosis may be altered by a comorbid condition such as coronary artery disease. Promptly and adequately treat a patient with iron deficiency anemia who is symptomatic with such comorbid conditions.
Chronic iron deficiency anemia is seldom a direct cause of death; however, moderate or severe iron deficiency anemia can produce sufficient hypoxia to aggravate underlying pulmonary and cardiovascular disorders. Hypoxic deaths have been observed in patients who refuse blood transfusions for religious reasons. Obviously, with brisk hemorrhage, patients may die from hypoxia related to posthemorrhagic anemia.
Whereas a number of symptoms, such as ice chewing and leg cramps, occur with iron deficiency, the major debility of moderately severe iron deficiency is fatigue and muscular dysfunction that impairs muscular work performance.
In children, the growth rate may be slowed, and a decreased capability to learn is reported. In young children, severe iron deficiency anemia is associated with a lower intelligence quotient (IQ), a diminished capability to learn, and a suboptimal growth rate.
