(go to Outline)
Oedema is fluid collection in the tissue. In some severely malnourished people, fluid leaks out of the blood vessels into the tissues causing a particular kind of swelling, called pitting oedema. Examination for pitting oedema consists of applying pressure with the thumb to the back of the foot or front of the lower leg for 3 seconds, then releasing. If a dent is seen or felt, pitting oedema is present. The examiner must press for at least 3 seconds and clearly see or feel a dent remaining after the pressure is released. Pitting oedema must be present on BOTH feet to be caused by malnutrition. There are many other causes of pitting oedema in only one foot. Pitting oedema if very often over-diagnosed by survey team examiners which leads to spurious conclusions about the prevalence of severe acute protein-energy malnutrition.