Hypercontractile esophagus (HE), also known as jackhammer esophagus, is an 
esophageal motility disorder. Nowadays, high-resolution manometry (HRM) is used 
to diagnose the disorder. According to the latest iteration of the Chicago 
classification, HE is present when at least 2 out 10 liquid swallow-induced 
peristaltic waves have an abnormally high Distal Contractile Integral. In the 
era of conventional manometry, a similar condition, referred to as nutcracker 
esophagus, was diagnosed when the peristaltic contractions had an abnormally 
high mean amplitude. Although the HRM diagnosis of HE is relatively 
straight-forward, effective management of the disorder is challenging as the 
correlation with symptoms is variable and treatment effects are dubious. In this 
mini-review, we discuss the most troublesome uncertainties that still surround 
HE, in the light of new data on etiology and epidemiology published in this 
issue of Neurogastroenterology and Motility.