If “ominous tingling” doesn’t concern you, then by all means, keep wearing those Spanx. It’s an issue raised by the L.A. Times after speaking to numerous doctors who treat patients for problems brought on by shapewear. The technical term is meralgia paresthetica and it results in painful burning in the thighs when excessive pressure is placed on the nerves that run through the groin. It can appear in pregnant women, those who’ve rapidly gained weight, and now, fans of Yummie Tummie.
Turns out, ominous tingling isn't the only concern. Shapewear and waist-training corsets can put excessive pressure on the stomach, pushing acid into the esophagus. “It's really just plumbing,” Jay Kuemmerle, a gastroenterologist explained to the L.A. Times. “For someone who has reflux disease or is prone to reflux, wearing tight garments may exacerbate those symptoms.” Gastroesophageal reflux disease causes heartburnlike symptoms in varying degrees of severity. Shapewear can also worsen IBS symptoms, exacerbate urinary incontinence, lead to UTIs, and cause skin infections (because it traps sweat).
“I'm not trying to say that everyone wearing restrictive garments is going to have problems,” Kuemmerle said, who went on to suggest that most of these problems go away when the patient stops using shapewear. Across the pond, doctors are a bit more concerned. “Control underwear is the 21st-century version of the corset, with all the same health risks,” says Richard Bricknell, director at the Bristol Physiotherapy Clinic, told the Daily Mail. Bricknell said that the pressure on the lower stomach could cause inflammation and ulcers. (Shapewear can also inhibit regular breathing, since some iterations compress the lungs.)
The medical community is not in complete agreement about the dangers posed by shapewear; some doctors believe it should come with a warning, others recommend wearing it very sparingly. Or, you could take the advice of one doctor and find a brand that “smooth[s] out the rough edges” but goes on and off “without a struggle.”