In this section, we will look at various types of malnutrition. What are these types? Acute malnutrition, this can come in severe or moderate forms. There are two different types: wasting or thinness – you saw this type also in the video, previously – and then there is a type of acute malnutrition with nutritional oedema – some call it oedematous malnutrition. Acute malnutrition can develop in a relatively short time; it can take some weeks or months to develop. This is in contrast to chronic malnutrition, stunting or shortness. This form takes generally longer to develop. It can be caused by having chronically inadequate food intake with or without suffering from diseases. It can also be caused through repeated episodes of acute malnutrition. The people affected by chronic malnutrition are short for their age, and it is marked by growth impairment in childhood and adolescence. Then another type of malnutrition is micronutrient deficiencies. This can be developed if a person lacks one or more vitamins or minerals. These micronutrients have all different functions in the body, and the deficiencies often lead to specific physical and/or mental problems. Overweight and obesity – they are also forms of malnutrition, in this case, of overnutrition. As I previously mentioned, I leave this type here aside and focus mainly on the various types of undernutrition. As both acute malnutrition and micronutrient deficiencies can contribute to high mortality in a disaster context, I want to focus in this module more on acute malnutrition and a little bit on micronutrient deficiencies. Let's go back to acute malnutrition again, and let's look more in detail at the first type I mentioned previously, the form we call wasting or thinness. This form of acute malnutrition is also called marasmus, that comes from the Greek word marasmos with a similar meaning or decay. It is relatively easy to diagnose as the symptoms are fairly obvious: gross muscle wasting, clear visible underweight, no fat visible and ribs can be easily seen. The body breaks down fat and muscle reserves to maintain essential functions – that leads to the thinness. You can see also so-called baggy pants. It looks like loose skin around buttocks. The hair color can be normal. Children show a little old man face. They are easily irritated, but usually they have appetite. Depending on the severity, there are severe and moderate forms. Children are particularly vulnerable to acute malnutrition, but it can also appear amongst adolescents and adults, a shift seen in the video film earlier in this module. Acute malnutrition compromises immunity and impairs many metabolic functions. If this form of malnutrition isn't treated, there's a higher risk of getting sick and dying especially amongst children. The good news is that it's relatively easy to treat, especially in the case if the person has appetite and has no major complications such as serious infections. A more difficult form of acute malnutrition is the one that comes with nutritional oedema. Some people, for reasons that we do not fully understand yet, get the type with nutritional oedema. Oedema basically stands for excessive retention of water in areas where you normally do not expect that. In this case, it manifests itself as swelling of the lower or upper limbs on both sides of the body – that's why we call it bilateral. In more advanced cases, other parts of the body can also be swollen. For example, the face – we call it moon face. We also call it pitting oedema. This means that when you press with your thumb a few seconds on the area with nutritional oedema, it leaves a pit behind the small dent. You can see that on the photo. Children affected by this have often also symptoms of damaged, peeling or depigmented skin. Their hair also gets often dry and can be pulled out easily. Sometimes the hair is discolored. This form of acute malnutrition is always severe and needs immediate specialized medical care. People with nutritional oedema are very sick and often apathetic. They are at a very high risk of dying. In early days, this form was called kwashiorkor. Here's some examples of children with nutritional oedema. So, how do we measure acute malnutrition? Well, this subject would be a whole module in itself, but let me try to explain that in a brief but clear way. We use what we call anthropometry for that. This means taking measurements of the human body, and certain cut-off point for these measurements correspond to severe or moderate acute malnutrition. There are a few anthropometric measurements we take when we speak about children aged six months to five years old. Firstly, we take the weight and height and we compare the values to a standardized table, and this will tell us whether the child is acutely malnourished. It can also tell us whether the child is suffering from severe or moderate acute malnutrition. We call this weight-for-height measurement. The other measurement we can take in children is mid-upper arm circumference or MUAC. If the circumference of the upper arm is very small, it means that the child has very limited reserves of proteins as the muscle is reduced. Remember the film we showed earlier? We saw that the calves and arms were all very thin. From extensive research, it has been proven that a small MUAC, which we measure in centimeters or in millimeters, correlates with mortality of the child. Of course, we also use the presence or absence of nutritional oedema as a way of diagnosing acute malnutrition. And if present, this stands for severe acute malnutrition. For adolescents and adults, we use different anthropometric measurements. For example, we can use BMI, which stands for body mass index, and in some circumstances, we use MUAC but with different cut-off points for adults than for children. I will not go in detail further on anthropometry. Here's some more images of MUAC measurements that are used to identify malnutrition. What is important to remember is that we see children under five years of age are often particularly vulnerable to acute malnutrition and that we see symptoms of malnutrition in this group often quicker than in adults; and children that suffer from severe acute malnutrition have up to 20 times higher risk of death compared to children that are well-nourished. This means it's very important to diagnose them quickly. Remember the two types of malnutrition that are specifically important in a disaster context? We just dealt with acute malnutrition, now a few minutes on micronutrient deficiencies or, as I call them, MNDs. MNDs are not easily detected and diagnosed. Thses are often based on a combination of looking for specific symptoms, analyzing the diet, and sometimes laboratory analysis. MNDs can be caused by inadequate nutrition. For example, iron deficiency can be caused by lack of iron in the diet. But certain diseases can also cause MNDs. To stick to the same example, iron deficiency can also be caused by malaria or by hookworm infestation. MNDs occur in disasters especially when there is a high burden of disease, such as aerial diseases, malaria, but also when there is a high level of food insecurity. When the diet is monotonous and people have access to only a few commodities, it's likely they will suffer from MNDs. Some of these efficiencies are disabling and can even be fatal. Various MNDs have been seen in humanitarian disasters, especially iron deficiencies, vitamin A deficiency but also deficiencies of the different B vitamins or vitamin C have been seen. The latter you might know better as scurvy which is especially prevalent in areas where people have no access to any fresh food. Some years ago, I remember very well, we had an outbreak of scurvy, vitamin C deficiency, in the west of Afghanistan near Herat. The country was in war, and access to roads was not always easy. Also, a few months of the year this area was completely covered in snow due to the lengthy winters. The area also suffered a drought the last consecutive four years and people had lost many assets. Fresh foods were hard to come by. Vitamin C is especially present in fresh vegetables and fruits, and because of the lack of these, we saw many cases of scurvy. Sadly, there were also quite a few death due to this. Amongst those affected, there was a 7% case fatality rate, and that corresponded to 323 deaths. So now we have discussed some types of malnutrition in detail, how could we possibly treat or prevent them? This is a topic for the next section.