While the exact cause of Paradoxical Adipose Hyperplasia (PAH) is still not known, it tends to affect about one in 138 people who receive CoolSculpting. During CoolSculpting, the goal is to freeze fat cells in order to break them down. However, in some cases, an opposite reaction can occur and increase the size of these cells, causing Paradoxical Adipose Hyperplasia (PAH). After these cells have expanded, they require more nutrients and oxygen, further their density, and making them harder. In most cases, Paradoxical Adipose Hyperplasia (PAH) will become noticeable about 1 – 2 months following a CoolSculpting treatment, but it can take up to six months for a proper diagnosis.