The left testicle hurts when you pinch it, along with the pain in the stomach may be related to the causes of left varicocele, left orchitis, left epididymitis and so on. 1. Left varicocele: Due to blood stasis in the varicose spermatic vein plexus, the scrotum looks more swollen and may radiate pain to the lower abdomen. 2. Left-sided orchitis: unilateral swelling of the testicle, redness of the scrotal skin, pain when pinching the testicle, which may radiate to the groin, abdomen and other places. 3. Left-sided epididymitis: testicular pain and pressure, pain or discomfort in the lower abdomen or pelvic area may occur. In addition, there are many other reasons that can cause pain in the left testicle when pinched, along with pain in the stomach. Patients should seek medical treatment in time to clarify the cause of the disease and standardize the treatment under the guidance of the doctor.