The latest example is the inguinal hernia which, in its mild form, may produce no symptoms at all. The wise doctor will delay surgery until the patient is in pain or discomfort - partly because he knows that surgical repair carries a long-term risk of recurrence, and itself can cause as much pain and discomfort as the hernia.
The watchful-waiting approach has been vindicated in a recent trial of 720 men with hernias, half of whom had immediate surgical repair, while the rest were treated to two years of watchful waiting. During that time, 17 per cent of patients experienced pain and so underwent surgery. Only two others in the watchful-waiting group experienced complications; the vast majority carried on in their everyday lives without a moment of pain, and without a need for surgery (JAMA, 2006; 295: 285-92).