https://next.amboss.com/us/article/jJ0_FS#Yf9b9106a59eac5e366e5072fdb85e8e2 says wall tension = (Ptm * r) / 2*h. I’m not really into physics so can’t comment further. Perhaps we could update the Extra to avoid confusion since it points users to the FA image which does say Wall stress = (P * r) / 2 * h.
FA 2024 says wall tension = P x R. FA 2024 also says Wall stress = P x R / 2 X wall thickness. So they are separate but AMBOSS seems to say that wall stress (from FA definition) is actually wall tension