Anaemia, which mainly affects women and children, is a condition that causes the number of red blood cells or the haemoglobin concentration within them to be lower than normal.
People with this condition are known as anaemics, and there are millions of them around the world.
In fact, the World Health Organisation (WHO) estimates that, overall, 40% of children between six months and 5 years of age and 30% of women between 15 and 49 years of age are anaemics.1
The symptoms associated with anaemia include fatigue, weakness, dizziness, and shortness of breath.
They are caused by anaemics' relative lack of haemoglobin, a protein needed to carry oxygen from the lungs to the rest of the body.
Anaemia is generally considered a symptom of an underlying health problem, which could be anything from a nutrient deficiency to an infection.
In medical circles, the type of anaemia caused by low iron levels is called iron deficiency anaemia and can be caused by:
Unsurprisingly, the condition can also be caused by a poor diet that is lacking in iron.
Low- and lower-middle income countries bear the greatest burden of anaemia, particularly populations living in poorer households in rural settings.2
Common symptoms of anaemia include:
In severe cases, symptoms can also include:
If left untreated, iron deficiency anaemia also affects your immune system and increases your risk of potentially serious health problems such as heart failure.
Globally, anaemia is estimated to affect half a billion women between 15 and 49 years of age, as well as 269 million children under five years of age.3
A simple blood test will confirm if you have iron deficiency (or another form of) anaemia. You can arrange this by making an appointment with your GP, who may then refer you to a specialist for further checks.
Anaemia can usually be treated successfully by taking daily iron supplements. But you may need to take them for six months before seeing the results.
In severe cases, other types of treatment, such as a red blood cell transfusion, may also be necessary.
Other things you can do if you are diagnosed with anaemia include:
If you take iron supplements, it's vital to keep the tablets out of the reach of children, as an iron overdose can be fatal to a young child.
Iron levels are generally measured via a blood test for something called ferritin, for which normal levels are 25 to 350 nanograms per millilitre for an adult man and 10 to 300 ng/mL for an adult woman, according to the NHS.
However, when it comes to the cause of the symptoms of conditions such as anaemia, haemoglobin levels are the main culprit.
The optimal haemoglobin concentration required to meet your physiologic needs varies depending on a range of factors including your age, your sex, and even what altitude you live at.
But for reference, current NHS thinking puts normal haemoglobin levels at somewhere between 130 and 180 grams per litre for men and 120 and 160 g/L for women.
If either your ferritin or your haemoglobin levels are outside these ranges, it could be a sign you have anaemia or another condition, such as haemochromatosis, which pushes your levels up rather than down.
Haemochromatosis is an inherited condition where iron levels in the body build up over many years, eventually causing unpleasant symptoms and potentially damaging organs such as the liver, joints, pancreas, and heart.
It is most common among people of white northern European background, especially those with a Celtic background (e.g., Ireland, Scotland, and Wales).
Haemochromatosis is caused by a faulty gene passed on by your parents.4
Haemochromatosis symptoms usually only become noticeable between the ages of 30 and 60. They include:
If the condition is diagnosed and treated early on, haemochromatosis does not affect life expectancy and is unlikely to result in serious problems.
But if it's not spotted, the high iron levels caused can lead to liver problems such as cirrhosis, as well as diabetes, arthritis, and heart failure.
Like anaemia, haemochromatosis is usually diagnosed by testing your blood, initially for iron levels and - if these indicate haemochromatosis - to see if your DNA carries the gene associated with the condition.
You may then also need further tests to check whether the condition has damaged organs such as your liver.
The most common treatment for haemochromatosis involves removing stored-up iron by draining some of your blood much as you would when donating blood.
This may need to be done regularly just after diagnosis but can usually be reduced to just a few times a year once your iron levels have come back down.
People who are unable to give blood frequently, for example because they have very thin veins, can also take medicine that removes iron from the blood, which is known as chelation therapy.
Other things you can do to help keep your haemochromatosis under control include cutting back on alcohol, which increases the strain on your liver, and not taking vitamin C supplements.