What Is Paradoxical Adipose Hyperplasia (PAH?)

Paradoxical adipose hyperplasia is a very rare side-effect of CoolSculpting. Learn more about the causes, symptoms, and treatment options here.

October 10, 2021

5 min read


Did you know that more than one million CoolSculpting treatments have been performed all over the world? CoolSculpting is an FDA-approved procedure designed to reduce fat on certain parts of the body. Its popularity has been rising ever since it was invented in 2005. 

While many swear by the results of CoolSculpting, it’s important to understand that there are some risks involved. One such rare side effect from CoolSculpting is paradoxical adipose hyperplasia, also known as PAH. If you’ve had CoolSculpting treatments before, you most likely don’t need to worry about this condition.

PAH only occurs in a small number of people who undergo CoolSculpting. Because it is so rare, many people don’t know about it. If you’ve never done a CoolSculpting treatment before, you’ll want to know more about PAH. 

Are there any determining factors that can let you know if you are prone to developing PAH after CoolScultping treatments? Is there any way of avoiding the development of this condition? Is it possible to treat the condition if you have it?

These are some of the many questions that we will explore as we delve deeper into what paradoxical adipose hyperplasia is. Let’s get started. 

What Is Paradoxical Adipose Hyperplasia?

Many people have never heard of paradoxical adipose hyperplasia because it is such a rare side effect. Recently, it has received more attention because of the famous supermodel Linda Evangelista.

Evangelista has spoken out about how she has been permanently disfigured after CoolSculpting treatments. This disfigurement is the result of PAH. But what is PAH exactly and what does it do to the body?

First, let’s explore a little bit about what CoolSculpting normally does to the body.

What Is CoolSculpting?

The method of CoolSculpting is cryolipolysis. Cryolipolysis is a procedure that involves squeezing an area of fat on the body between two plates that reach freezing temperatures. This freezes fat cells in the body and kills them. 

What happens to the dead fat cells?

Thanks to the hard work of the liver, these fat cells are removed from the body over a period of weeks or months. After several months, these fat cells have not been seen to return. In fact, it is believed that the removal of these fatty areas has permanent effects.

This, of course, is great news for people looking to reduce certain bulges of fat on their bodies. This is especially true for those who have trouble losing weight in certain areas of their body.

The most popular areas to receive CoolSculpting are the inner thighs, the buttocks, the love handles, and the abdomen. Some people also receive the treatment on their necks to reduce the appearance of double chins. Another benefit of CoolSculpting is that it can reduce the appearance of cellulite. 

CoolSculpting is sought after by many people because it is a simple, painless procedure that lasts about an hour. Who wouldn’t want to almost immediately get rid of stubborn fat? 

Although CoolSculpting is a miracle to many people, we shall see that, in some cases, it can have some negative consequences. 

Causes of Paradoxical Adipose Hyperplasia

Unfortunately, there doesn’t seem to be any signs to predict which patient will get PAH. PAH is such a rare side effect of cryolipolysis that it is believed less than 1% of all people who undergo CoolSculpting treatments will experience it. Because it is so uncommon, there is very little scientific information on the condition. 

Since the usual side effects of CoolSculpting treatments include temporary redness, tingling, and numbness, PAH can be considered a much more serious side effect. Fortunately, now that more people are becoming aware of PAH, medical professionals are taking into account possible triggers. 

In addition to being rare, PAH can take a long time to diagnose. This is adverse side effect is often very delayed. PAH can start to show itself around 6 months after the initial CoolSculpting treatment. 6 months is the marker for when people who do not have PAH start to see the beneficial results of CoolSculpting the most. 

It is also unknown why it takes so long for the effects of PAH to appear in the body. The effects of PAH also appear to be permanent if treatment is not pursued. 

Let’s take a closer look at what paradoxical adipose hyperplasia looks like on a physical level. 

The Theory

There is one theory that attempts to explain this phenomenon. The theory is that it may be possible that some fat cells in the body, also known as adipose tissue, are more resistant to freezing cold temperatures than other fat cells. It is unknown why this would be the case.

Following this theory, if some fat cells are more resistant to CoolSculpting, they may refuse to shrink and die as normal fat cells do. Instead, these stubborn fat cells go into survival mode and increase their size in order to subsist. This is possible because of the activation of certain molecules that allow for the growth of blood vessels. 

With new blood vessels supplying blood to the affected fat cells, these fat cells are nourished and grow to abnormally large sizes. 

Signs and Symptoms of Paradoxical Adipose Hyperplasia

Those who experience paradoxical adipose hyperplasia can be very distressed because the results are the opposite of what CoolSculpting promises to give. Instead of killing and allowing for the removal of fat cells, PAH actually increases the size of fat cells. 

The affected area does not look fuller and fattier. Instead, the affected area looks irregular and raised. Instead of soft to the touch like ordinary fat, the fat that PAH impacts is firm.

Often, the shape of the fat affected by PAH is the shape of the CoolSculpting application tool. This shape is usually rectangular and has been nicknamed as having a “stick of butter” appearance. Serious cases of PAH can be much worse than the simple “stick of butter” look. 

For example, the treatment area may consist of several hard knots of fat. Certain areas may also bulge or be especially pronounced in asymmetric ways. Overall, the area affected by PAH is visibly deformed in profound ways. 

While tissue affected by PAH is not painful or physically dangerous, it can be very upsetting to those that have this condition. 

Treatments For Paradoxical Adipose Hyperplasia

Anyone interested in CoolScuplting after reading this article is sure to be wondering how to avoid getting paradoxical adipose hyperplasia. Unfortunately, since not much is known about the cause of PAH development, there is also not much information about how to avoid it. 

It is important to keep in mind that PAH is a very rare side effect that impacts less than 1% of all people who undergo CoolSculpting treatments. More likely than not, you will not get PAH after cryolipolysis treatments. 

Talking about treatments, are there any treatment options available for PAH? Thankfully, there are. Unfortunately, it may take some time for those with PAH to be treated. 

First of all, those with PAH usually need to wait around nine months to be treated. This is because the affected fat is often too firm to be treated right away. By the nine-month mark, the abnormal fat cells have softened enough to be treated. 

For those with PAH, waiting this long can be torture. No one wants to feel powerless over the part of their body that has been deformed. However, the wait is worth it to get rid of the abnormal fat cells and return to a normal appearance. 

Those who have PAH should not undergo more CoolSculpting procedures as this can worsen the PAH further. Instead, alternative fat removal procedures should be chosen. A popular option for PAH is liposuction or Kybella

Liposuction for PAH

Liposuction does not use the cryolipolysis method. Instead of freezing and killing fat cells, liposuction works by physically removing fat cells with a suction tool. The results of liposuction are permanent as long as a stable weight is maintained. 

Liposuction results are also instant. All of the bumpy and uneven fat cells affected by PAH can be removed. The final result is a smooth and sculpted body

Depending on how severe the PAH, multiple treatments may be required. However, PAH is generally considered a very treatable condition. If you have undergone CoolSculpting treatments and found yourself with PAH, there is plenty of hope for treatment. 

Answering the Question of Paradoxical Adipose Hyperplasia

Now that you understand the benefits and risks of CoolSculpting, you also are wiser about paradoxical adipose hyperplasia. PAH is a very rare adverse side effect of CoolSculpting that impacts less than 1% of patients. It is unknown why PAH occurs, but there are treatment options available. 

Even though PAH is rare and not much cause for concern, it is always important to weigh the risks of any cosmetic procedure you undergo. 

Browse around to learn more about the difference between CoolSculpting and liposuction as well as other procedures.

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