Diagnosed with small sliding hiatus hernia no heartburns but sharp chest pain which radiates to back sometimes. is this condition serious ? ty

Hiatal hernias: If small, no. Could have resultant reflux pain, which stems from stomach acid going back up the esophagus. You are at risk for this because of the hiatal hernia, & usually is present after eating something spicy, fatty or really heavy. Avoid foods like above as well as smoking, alcohol & medications like Aleve/Advil/Motrin. See a GI specialist or Surgeon for possible repair, if the pain continues.