Iron deficiency anemia is a condition in which a person has too few red blood cells, caused by low levels of iron in the body. The body needs adequate levels of iron for the production of hemoglobin in red blood cells, which is the component of blood that transports oxygen through the body and gives blood its characteristic red color. If there is a shortage of iron in the body, the bone marrow produces less red blood cells, which are also smaller in size. As a result of their reduced number and size, these red blood cells carry less oxygen to tissues, which leads to the symptoms of anemia.
The spongy, vascular or fatty tissue found inside bones, responsible for producing blood cells.
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
Iron is typically absorbed by the gastrointestinal tract, which consists of a membrane-lined series of organs extending from the mouth to the anus through which food passes during digestion. The iron is then carried in the blood to the liver, where it can be stored or moved onto the bone marrow to form hemoglobin within red blood cells. The body then recycles the iron from old and worn-out red blood cells to make new ones.
The spongy, vascular or fatty tissue found inside bones, responsible for producing blood cells.
The membrane-lined series of organs extending from the mouth to the anus through which food passes during digestion.
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
A large, internal organ of the body, located on the upper right-hand side of the abdomen. The liver has hundreds of distinct functions, including producing bile, regulating the body's metabolism and detoxifying the blood.
Blood loss is the most common cause of iron deficiency anemia. It might not always be obvious, such as when it occurs due to trauma, surgery or in women with heavy menstrual bleeding. For example, slow bleeding of the gastrointestinal tract in some circumstances is not visible and can often go unnoticed.
A less common cause of iron deficiency anemia is decreased iron absorption. However, if the gastrointestinal tract is inflamed, or if you have a condition such as coeliac disease, you might not absorb enough iron, which can lead to iron deficiency anemia.
A lack of iron-rich food in developing countries is a cause of iron deficiency anemia in these places. In contrast, many developed countries have food with added iron. However, if you are vegetarian or if you do not eat enough red meat, you may not get all the iron you need, due to the fact iron is not as readily absorbed from plants as it is from meat.
If you are pregnant, your iron requirements are greater and if your intake is inadequate, you might develop iron deficiency anemia.
The membrane-lined series of organs extending from the mouth to the anus through which food passes during digestion.
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
Some of the risk factors for developing iron deficiency anemia include:
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
A type of weight-loss surgery that permanently reduces the stomach capacity and is designed for the food to bypass some of the small intestine to reduce absorption of calories.
Sometimes, people with iron deficiency anemia have no symptoms. When they do, common symptoms include:
Iron deficiency anemia can cause fatigue and weakness.
Other symptoms that are not as common include:
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
A disorder that causes persistent and compulsive cravings for substances that are not food, such as dirt, coal, ice, or hair.
A neurological disorder that causes unpleasant sensations in your legs such as itching, tiredness, soreness or twitching, and an associated compelling need to move your legs. It is usually experienced when trying to sleep but can occur during the day when symptoms are generally less noticeable.
Because there are many potential causes of iron deficiency anemia, a full history needs to be taken and physical examination performed by your doctor to identify the most likely cause of iron deficiency or blood loss. Relevant investigations will be performed according to your individual circumstances.
Using your blood sample, the number of red blood cells (erythrocytes), white blood cells (leukocytes) and platelets (thrombocytes) will be assessed.
This test assesses the size, shape and color of red blood cells under a microscope. In iron deficiency anemia, the red blood cells are typically small (microcytic), lacking in color (hypochromic) and fewer in number than in healthy blood samples.
Your blood will also be tested for iron levels and related proteins, such as ferritin, which help in the storage of iron.
A blood test is used to analyze hemoglobin levels and assess red blood cells.
The gastrointestinal tract can be a source of a wide range of conditions that cause iron deficiency anemia so is often the focus of investigation if another cause is not obvious. Even if another cause, such as heavy menstrual periods, is present, your doctor may still wish to evaluate your tract to ensure you are not suffering with a concurrent cause.
Iron deficiency anemia of unknown cause may be caused by 'occult' (hidden) bleeding or malabsorption from the gastrointestinal tract. Investigations may include:
Further blood tests may be performed to investigate for inflammation, coeliac disease or other deficiencies, such as vitamin B12 or folate, that may occur if the bowel is generally not absorbing substances well.
A fecal occult blood test (FOBT) detects blood in your feces. It is most commonly used as a screening test for bowel cancer, but bleeding could be due to other causes. You will need to provide two samples on separate occasions, as bleeding can occur intermittently. FOBT may be helpful to detect if there is any bleeding from the gastrointestinal tract but may in some cases have false negatives. Further testing of the tract is often carried out even if you have a negative FOBT.
A colonoscopy is used to examine the length of the colon (large bowel). Before the procedure, your bowel will be prepared using an oral laxative solution and sometimes an enema washout. You can also help prepare your bowel by not eating but drinking plenty of clear fluids in the 12-24 hours prior. During a colonoscopy, a long tube with a camera called a colonoscope is inserted into your bowel through the anus. Air will be pumped into your colon to allow your doctor to see it properly. This procedure can help diagnose conditions of the bowel such as diverticular disease, bowel cancer and Crohn's disease that may be causing blood loss.
During an upper endoscopy you'll be sedated and a long, narrow, telescopic camera will be gently fed down the esophagus and into your upper digestive system. Ulcers, cancers or inflammation of the esophagus, stomach or small bowel may be seen. Biopsies may be taken to look for inflammation, infection or coeliac disease. All of these conditions can lead to iron deficiency anemia.
In some circumstances, where the cause of bleeding is not found with gastroscopy or colonoscopy, the remainder of the small bowel may need to be examined. Wireless capsule endoscopy may be used, in which a small capsular camera is swallowed and passes through the entire length of the bowel recording the bowel's appearance. Other investigations may include a small bowel follow-through, or radionuclide scanning, depending on your circumstances.
The removal of a tissue sample for microscopic laboratory examination. It is used to determine the presence, cause and type of the disease.
The part of the large intestine that leads to the rectum.
A procedure in which fluid or gas is injected into the rectum for cleansing, diagnostic or therapeutic purposes.
The membrane-lined series of organs extending from the mouth to the anus through which food passes during digestion.
A body’s protective immune response to injury or infection. The accumulation of fluid, cells and proteins at the site of an infection or physical injury, resulting in swelling, heat, redness, pain and loss of function.
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
Any substance that causes or encourages bowel movements.
Also called the gullet or food pipe, it is the muscular tube connecting the throat and stomach. It is lined with a mucous membrane. After ingestion, food and drink travel down the esophagus to be digested in the stomach.
An open sore in the skin or mucous membranes such as those of the stomach lining, intestine or mouth.
An imaging technique for visualizing body parts, such as organs and bones, by injecting a small amount of radioactive material into the body.
Ideally, treatment of the underlying cause of iron deficiency or blood loss aims to correct the deficiency and anemia. Sometimes oral or intravenous supplementation of iron is required, depending on the cause and/or severity of your iron deficiency anemia.
Oral iron supplements come in a few different forms. Types of oral iron include ferrous fumarate, ferrous gluconate and ferrous sulfate in tablet or liquid form. It is generally recommended that people with an iron deficiency need 100 to 200 mg of elemental iron per day. Be sure to discuss dosage with your doctor, as the amount of the ferrous salts can be different to the level of elemental iron in the preparation. For example, a 325 mg ferrous sulfate tablet contains 105 mg of elemental iron. Taking too much iron can be dangerous for the body.
Taking iron tablets with food, calcium supplements, antibiotics, or drinks other than water (especially milk products) reduces the absorption of iron. Taking iron tablets with vitamin C tablets or orange juice increases the absorption of iron, because iron is best absorbed in an acidic environment.
Slow release polymer-coated iron tablets are not used to treat iron deficiency, as iron is best absorbed in the first part of the intestine and their coating means they are not absorbed until too far down the tract.
If you cannot tolerate oral iron supplements, or your gastrointestinal tract is unable to properly absorb iron, then iron can be given as an infusion into the veins (intravenous).
Blood transfusions involve the administering of packed red blood cells into your bloodstream. Usually one or two units are required in people with iron deficiency anemia. Each unit contains roughly 200 mg of iron. There are certain risks with blood transfusions, so these are generally reserved for those with very low red blood counts.
The membrane-lined series of organs extending from the mouth to the anus through which food passes during digestion.
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
Side effects of oral iron include nausea, constipation and vomiting. These side effects can be reduced by lowering the iron dose, or taking the liquid form of ferrous sulfate and adjusting the amount you take. Iron also turns your stool very dark, almost black in color. This is expected and is not a problem.
Children under six years of age are at risk of iron poisoning, so it is important to keep your iron tablets out of their reach.
Side effects of parenteral iron include itching, heart palpitations and dizziness. Iron dextran is a type of parenteral iron that can cause allergic reactions, which can be life-threatening. Non-dextran forms of parenteral iron, such as iron sucrose and ferric gluconate complex, carry much less risk and are used for that reason. Iron infusions are carried out under medical supervision in case of any adverse reactions.
The most common side effects of a blood transfusion are mild shortness of breath, fever and chills. Rare side effects include incompatibility reactions and infection with hepatitis C virus or HIV. However, rigorous blood donor screening and blood testing makes these extremely rare in the US.
Iron deficiency anemia leaves you feeling lethargic and unproductive, making it difficult to stay awake or exert energy on activities such as exercise.
Iron deficiency anemia weakens your immune system, making you more likely to become ill as a result of infection.
If the anemia is severe, you are at risk of developing heart and lung complications such as a fast heart rate or heart failure.
If you are pregnant and have severe anemia, it can increase the chances of your baby being born prematurely, having a low birth weight, having problems with their iron levels and poor performance in mental aptitude tests later in life. You are at risk of the same complications otherwise experienced in iron deficiency anemia and can have an increased risk of developing postnatal depression.
Restless leg syndrome is thought to sometimes result from iron deficiency anemia. It is a common condition that affects the nervous system, resulting in unpleasant sensations in your legs such as itching, tiredness, soreness or twitching, and an associated compelling need to move your legs. It is usually experienced when trying to sleep, but can occur during the day when symptoms are generally less noticeable.
A problematic physiological response to an allergen that comes into contact with the body.
A virus transmitted mainly by sexual or blood-to-blood contact, that infects cells of the immune system. It is the causative agent of acquired immune deficiency syndrome (AIDS).
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
A neurological disorder that causes unpleasant sensations in your legs such as itching, tiredness, soreness or twitching, and an associated compelling need to move your legs. It is usually experienced when trying to sleep but can occur during the day when symptoms are generally less noticeable.
Liver inflammation caused by the hepatitis C virus, which is commonly spread through unsafe sex and blood-to-blood contact.
Depression that develops in a mother following childbirth, usually due to a combination of factors such as hormonal and psychological changes and fatigue.
Treatment continues until your red blood counts return to normal. You may still need to take iron supplements for a period of time after this to restore your iron stores. Some people do not respond to oral iron, in which case further testing is required to find out why. However, it may simply be that they were wrongly using slow-release iron tablets, or that they were not taking them as prescribed by their doctor.
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.
Eating a balanced diet usually provides you with enough iron to meet your body's needs. Most of the time iron supplements will not be needed, as increasing dietary iron is enough to maintain iron stores.
If you have had iron deficiency before, you are at increased risk of getting it again, so daily iron supplementation, as prescribed by your doctor, may be used to prevent iron deficiency anemia from returning. It is important to consult your doctor first, otherwise you risk an iron overdose.
Foods rich in iron are part of a balanced diet.
An essential mineral required by the body. Iron is part of a protein in the blood called hemoglobin, which carries oxygen around the body.