Abbey Sharp says she got PAH after CoolSculpting. What is it?

Dietitian Abbey Sharp is best known for her YouTube channel Abbey's Kitchen, where she unpacks diet culture, talks "hunger-crushing combos" and tries her own healthy spin on celebrity's professed diets. But earlier this month, the Toronto-based food personality took to her channel to speak about something else: her negative experience with CoolSculpting, which, she said, caused her to grow pockets of fat in the areas she was hoping to have it removed.

Sharp's experience with CoolSculpting was about a decade ago — when the procedure was still new to the market, having been approved by the FDA in 2010. Sharp said she was getting a facial at a medical spa when she saw advertisements for CoolSculpting, the body contouring procedure that aims to reduce fat via a method called cryolipolysis.

During the procedure, which lasts about an hour, suction-like paddles are placed on the area being treated. Popular areas including the stomach, flanks and under the chin. The goal of the treatment is to freeze and crystallize fat cells under the skin so they're ultimately destroyed, leaving you slimmer in the treated areas. Although full results aren't noticeable for months and multiple treatments are often required, the procedure is often hailed as a safe, less invasive alternative to liposuction, due to its lack of downtime. CoolSculpting has received praise from Gwyneth Paltrow's website Goop and Khloé Kardashian.

Sharp — who battled orthorexia, or an obsession with healthy eating, in the past — says she never felt that she had a flat stomach and was told by the med spa that CoolSculpting could help her achieve one. Because Sharp was already slim, she was told that she was an ideal candidate and that her "trouble" spots could be specifically targeted.

"That's how it was sold to me," Sharp tells Yahoo Life. "It was like, 'This is a no brainer. It's less invasive than Botox.' That's the vibe I was getting."

Sharp says she did two or three sessions, but after a few months, she noticed something odd about the areas treated by CoolSculpting.

"There were more almost like lumps or bumps that weren't there before and my body looked uneven," she explains. "My side started to look more uneven, my lower belly had a bulge that wasn't on the other side. So I thought, let's go back and see what we can do about this. I was never told that CoolSculpting could cause any of this — it made absolutely no sense in the context of the way CoolSculpting was described to work."

Sharp returned to the med spa, where she was given a free extra CoolSculpting session. She noticed no difference in her body — the lumps remained. It wasn't until a decade later that Sharp came to believe the still-noticeable bulges were from a little-discussed potential risk of CoolSculpting, known as paradoxical adipose hyperplasia (PAH).

Sharp is not the first to speak out about PAH. In fact, the YouTuber says she first made the connection between CoolSculpting, PAH and the lumps left on her stomach thanks to supermodel Linda Evangelista. In 2021, Evangelista shared that she suffered severe PAH after doing CoolSculpting, and was suing Zeltiq Aesthetics, the company behind the procedure (which is now owned by Allergan).

"PAH has not only destroyed my livelihood, it has sent me into a cycle of deep depression, profound sadness and the lowest depths of self-loathing," the supermodel shared on social media at the time. "In the process I have become a recluse."

Evangelista settled her lawsuit against CoolSculpting's parent company, Zeltiq in July 2022 for an undisclosed sum.

PAH refers to overgrowth of fatty tissue. The official CoolSculpting website lists paradoxical hyperplasia as some of the "rare" additional side effects of CoolSculpting, along with "late onset pain, freeze burn, vasovagal symptoms, subcutaneous induration, hyperpigmentation and hernia."

According to manufacturer data, PAH occurs in 1 in every 4,000 treatments — yet that data may not tell the whole story. Not everyone who experiences PAH will report it to their doctors, who can then report it to Zeltiq. Sharp, for example, was initially unaware of PAH and the connection to her CoolSculpting procedure.

In 2017, Dr. Jared Jagdeo, a dermatologist who was a consultant for Zeltiq at the time, co-authored a journal article suggesting PAH be considered a more common risk.

"Underreporting of PAH may be due to the highest volumes of cryolipolysis treatments occurring at medical spas or body contouring centers with patients who are not closely supervised by physicians or well-trained medical professionals who can identify PAH and report cases of PAH to the manufacturer," the article reads. "Also, PAH may be subtle so detection can be difficult depending on the degree of PAH. We predict that as the number of cryolipolysis procedures increases over time and becomes widely available, the incidence of PAH may also increase as increased awareness among medical providers and patients may lead to diagnosis and reporting."

Exactly why PAH happens after CoolSculpting treatments is unclear, and more research is needed to assess whether PAH may be due to the technique of the procedure, type of machine used or even a biological reaction within certain patients. A 2020 study says that more than 76% of studied PAH cases were associated with older models of CoolSculpting units.

New York-based plastic surgeon Dr. Mark Epstein says he uses CoolSculpting in his practice with good results. He tells Yahoo Life he has yet to see a patient with PAH.

"CoolSculpting is not like snapping a picture on your iPhone. It is extremely technician dependent," he says. "The people in my organization who do CoolSculpting attend CoolSculpting University and receive the highest level of certification performing the procedure, so that you can properly screen patients to minimize complications and perform the procedure the best way to minimize complications."

He adds that there are also two different CoolSculpting systems out there: the Legacy system and the newer Elite system. He uses the latter in his practice, adding, "If you're treating with antiquated equipment, then you're not going to get the same results."

Yet not every plastic surgeon is sold on CoolSculpting, partly because of the potential of PAH. New York City-based plastic surgeon Dr. Chris Funderburk regularly treats patients who have had negative outcomes following CoolSculpting and thinks there are too many unknowns right now.

"We just don't have any good data on this," he says of the reason why PAH occurs. "We don't know what settings to use to avoid PAH. We don't know what generation of machine to use, or paddles, in order to avoid it. It's all still a mystery, unfortunately."

His advice for those seeking CoolSculpting?

"I would say, either don't do it, or pause and let the dust settle so we can figure out that complication rate," Funderburk tells Yahoo Life. "The literature will be evolving pretty dramatically in the next year or two. I wouldn't rush out and get CoolSculpting right now until it's just better understood. And then I would say that they should go into it with the understanding that PAH is most likely more common than was previously reported."

Wellness, parenting, body image and more: Get to know the who behind the hoo with Yahoo Life's newsletter. Sign up here .