The classic "bag of worms" sensation you are feeling in your left scrotum strongly indicates a varicocele. This is an enlargement or dilation of the pampiniform venous plexus—the veins that drain blood from the testicle—very similar to varicose veins seen in the legs.
It is incredibly common for varicoceles to occur on the left side due to anatomical differences in how the left testicular vein drains into the
kidney vein. The reason your left testis feels smaller or less firm is that the pooled, stagnant blood increases the local temperature and pressure inside the scrotum, which can cause mild testicular atrophy (shrinkage) over time. It is a very good sign that your libido is healthy and you have no pain, confirming that this is not an acute emergency, but it does require a clinical look to protect your long-term testicular health.
Next Steps
Consult a Urologist: You should schedule a routine appointment with a urologist for a proper physical examination (grading the varicocele while standing and during a Valsalva maneuver).
Get a Scrotal Color Doppler Ultrasound: This non-invasive imaging test is the gold standard diagnostic tool to confirm the diagnosis, measure the exact size of your testicles, and evaluate the severity of blood reflux in the veins.
Undergo a Baseline Semen Analysis: Because the increased heat from a varicocele can affect sperm count, motility, and morphology, a semen analysis is highly recommended to ensure your fertility parameters remain entirely healthy.
Health Tips
Avoid wearing loose boxers or going without support during physical activities. If left unsupported, gravity can increase blood pooling, which may eventually lead to a dull, aching pain or worsen tissue softening over time.
Wear Supportive Underwear: Switch to snug-fitting briefs or a scrotal support jockstrap, especially when exercising or standing for long hours. This helps reduce venous pooling and takes the pressure off the testicular cords.
Avoid Straining: Try to avoid heavy lifting and chronic constipation, as straining increases intra-abdominal pressure, which directly pushes more blood back down into the scrotal veins.