Iron deficiency is a common cause of anemia. Anemia causes pale skin, fatigue, difficulties with concentration and general weakness. Anemia can usually be treated effectively.

At a glance

  • A person with anemia does not have enough red blood pigment (hemoglobin) in their blood.
  • This causes pale skin, fatigue and general weakness.
  • Iron deficiency is a common cause of anemia.
  • Eating a balanced diet can help avoid an iron deficiency but also a deficiency of vitamin B12 and folic acid.
  • Anemia frequently affects those aged over 65 and pregnant women.

Note: The information in this article cannot and should not replace a medical consultation and must not be used for self-diagnosis or treatment.

Woman lying on a couch supported on a few pillows. She is clutching her head and looks exhausted.

What is anemia?

Anemia is a condition in which a person’s blood contains significantly fewer red blood cells or significantly less of the red blood pigment hemoglobin than is considered normal. Red blood cells transport oxygen from the lungs to the cells of the body. This means that anemia causes an inadequate supply of oxygen to the body.

One common cause of anemia is a shortage of iron in the body. Iron plays an important role in many processes in the body. For example, the body needs iron to produce hemoglobin.

Older people often suffer from anemia.

What are the symptoms of anemia?

The most common symptoms of anemia are pale skin, fatigue, headaches and feeling weak or lightheaded.

Other possible signs of anemia are:

  • trouble concentrating and learning difficulties
  • shortness of breath during physical exertion
  • chest pain, heart palpitations, low blood pressure, fainting

What causes anemia?

Iron deficiency is the commonest cause of anemia.

Iron deficiency is the commonest cause of anemia.

Other causes of anemia include:

  • a deficiency of vitamin B12 or folic acid
  • chronic health conditions, such as kidney disease
  • blood cancer or diseases of the bone marrow

Why is iron important and how does an iron deficiency develop?

We get iron from our food. Iron is absorbed into the body through the mucosal lining of the entire digestive tract and the small intestine in particular. The blood then carries the iron to specialized cells, especially in the bone marrow, which incorporate the iron into the red blood pigment hemoglobin. Hemoglobin is an important component of red blood cells. These travel through the blood vessels, supplying the body with oxygen. If the body lacks iron, then it will also be lacking in the red blood pigment hemoglobin, and this may lead to a shortage of oxygen.

Iron is also important for muscles and many metabolic processes. The body stores excess iron, e.g. in the liver. From there, it can be released whenever the body needs it.

An iron deficiency may occur if the body loses more iron that it is able to absorb. That can happen, for example, if:

  • the person’s diet contains too little iron
  • too little iron is absorbed through the gut due to a health condition such as gluten intolerance (celiac disease)
  • a chronic loss of blood occurs, e.g. after an injury to the gastrointestinal tract, due to gastritis or when a woman has heavy menstrual bleeding
  • the individual has a chronic inflammatory disease, such as rheumatoid arthritis or a bowel disease
  • the iron deficiency is congenital (i.e. is present at birth), though this is rare

Important: Certain medications can cause bleeding in the gastrointestinal tract to become heavier. These include, for example, anti-inflammatory pain medication for osteoarthritis and blood-thinning medication used to treat atrial fibrillation.

What other causes are there?

In hemolytic anemia, red blood cells are broken down too quickly and cannot be replenished quickly enough. This occurs, for example, if there are congenital deformities of the red blood cells or if the normal metabolism of hemoglobin (i.e. production and breakdown of the red blood pigment) is disrupted.

Older people produce fewer red blood cells overall, and those they produce are broken down more quickly in the bloodstream. This can lead to age-related anemia.

In some cases, however, the cause of the anemia cannot be detected.

What factors contribute to anemia?

Temporary anemia may occur during pregnancy because the pregnant mother’s body has to produce red blood cells for the unborn baby too. In fact, towards the end of pregnancy, up to 50 percent more blood may be circulating through the expectant mother’s body, while the number of red blood cells in the blood only increases by a quarter.

Women who have heavy periods are also at an increased risk of developing anemia.

In addition, the risk of anemia rises with advancing age. The body needs the hormone testosterone to produce red blood cells. However, testosterone levels decrease as we age – in men and women alike. This then affects blood production.

How common is anemia?

In Germany, about 10 percent of adults have anemia, with women affected far more frequently than men.

In Germany, about 10 percent of adults have anemia, with women affected far more frequently than men.

However, both women and men become more susceptible to developing age-related anemia in older age – it is estimated that around 25 percent of those aged over 85 have anemia.

What is the outlook for anemia?

Anemia usually develops slowly and often remains undetected for a long time. Over time, the body becomes accustomed to having less oxygen available.

However, anemia can have long-term consequences if left untreated. For example, anemia can sometimes increase the risk of thrombosis (blood clots).

In people over the age of 65, even mild anemia can cause a decline in physical fitness. The risk of cardiovascular diseases, such as heart failure or heart attack, is also increased.

How can anemia be prevented?

People need iron to produce red blood cells and ensure that the body receives an adequate supply of oxygen. Normally, most of our iron requirements are covered by eating a balanced diet.

In some situations – for example, during pregnancy or breastfeeding – taking an iron supplement in tablet form can help prevent anemia. Iron supplements are equally beneficial to those experiencing heavy periods. It is important to consult a doctor before taking an iron supplement.

Anyone following a vegan diet should take care to ensure that they eat enough foods rich in iron and folic acid. Foods that are rich in iron and folic acid include nuts, sprouts, pulses (legumes) and green leafy vegetables, such as spinach.

For more information about how to get all the iron you need and which foods have a high iron content, see

How is anemia diagnosed?

An in-depth consultation with a doctor is required before anemia can be diagnosed. The doctor will take a detailed medical history, asking the patient, for example, about:

  • eating habits
  • alcohol consumption
  • current or previous illnesses
  • any medication the patient is taking

Next, various tests will be run on a blood sample. For example, the level of the red blood pigment hemoglobin will be determined and the number of red blood cells will be checked.

The levels of iron, vitamin B12 and folic acid in the blood can also be measured to detect any potential deficiency. In addition, certain indicators in the blood enable the detection of kidney diseases or inflammations (which increase the risk of anemia). A blood count will also indicate whether the person has any health conditions affecting the red blood cells.

If an iron deficiency cannot be explained by an insufficient intake of iron in the diet, the doctor may investigate whether the cause could be an inflammation of the bowel. They will also check, for example, whether minor wounds in the bowel could be causing chronic blood loss.

In particular in those aged over 65 with unexplained anemia, doctors will investigate whether a disease of the bone marrow could be responsible.

How is anemia treated?

In cases where anemia is caused by chronic inflammation or blood loss, these pre-existing conditions must be treated first. If the cause is an iron deficiency, experts often recommend consulting a nutritionist.

Important: Certain substances inhibit the body’s ability to absorb iron. These are found in black tea, coffee and milk products, for example. Therefore, these should not be consumed in combination with an iron supplement.

If someone is suffering from severe anemia due to cancer or renal insufficiency (poor kidney function), doctors can use medication to stimulate the production of red blood cells. In the event of major blood loss, red blood cells can be supplied via a blood transfusion.

In cooperation with the Institute for Quality and Efficiency in Health Care (Institut für Qualität und Wirtschaftlichkeit im Gesundheitswesen – IQWiG).

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