What could cause slight pain in my left testicle and groin discomfort after a week?

Pain in the left testicle and accompanying groin discomfort can be concerning and can stem from several underlying conditions. Given your description, a few possibilities come to mind. One potential cause could be an inguinal hernia, where part of your intestine or abdominal tissue protrudes through a weak spot in the abdominal muscles, sometimes affecting the groin and potentially leading to discomfort in the testicle as well. Another possibility is epididymitis, an inflammation of the epididymis, often caused by infections, though your lack of sexual activity in recent years may make this less likely. Sometimes, testicular torsion or intermittent torsion can cause similar symptoms, which is a medical emergency. While torsion is more common in younger males, it shouldn’t be fully ruled out and warrants urgent assessment. Testicular cancer, though often painless, can also present with discomfort or ache in the area and is more frequent in younger males, but vigilance is still recommended. Lastly, referred pain from the kidney, such as from a kidney stone, can occasionally manifest as testicular pain. Since some of these conditions could become serious if untreated, it’s essential to see a healthcare provider for a proper examination and possible imaging tests, like an ultrasound, to get a clearer understanding of the cause. Until then, avoiding heavy lifting or straining may help reduce discomfort. Keep an eye on any changes, particularly increased pain, redness, or swelling, and seek prompt medical care if these occur.