What is a varicocele?

A varicocele is a widening (dilation) of the veins that drain the testicle, similar to varicose veins in the legs. It develops when the one-way valves inside these veins fail, allowing blood to pool and the veins to enlarge. Varicoceles are common — they affect roughly 15% of adult men, and up to 40% of men evaluated for infertility (American Urological Association). The good news is that most are harmless, and the ones that cause symptoms or affect fertility can be treated with a quick, minimally invasive procedure.

10 varicocele symptoms you should not ignore

1. A dull, aching discomfort

The classic symptom is a dull ache or dragging discomfort in the scrotum rather than sharp pain. It is often mild and easy to dismiss.

2. Pain that worsens with standing or exertion

Discomfort typically builds during long periods of standing, physical activity, or heat exposure, because gravity increases the pooling of blood.

3. Relief when lying down

Lying flat lets the pooled blood drain, so the ache often eases within minutes. This day-night pattern is a helpful clue.

4. A visible or palpable bag of worms

Enlarged veins can be felt — and sometimes seen — as a soft, twisted mass above the testicle, most obvious when standing or bearing down.

5. A feeling of heaviness

Many men describe a sensation of fullness or heaviness in the scrotum that grows through the day.

6. Left-sided predominance

Around 85 to 90% of varicoceles occur on the left side because of how the left testicular vein drains. A varicocele that appears suddenly on the right side should always be checked by a doctor.

7. Testicular shrinkage (atrophy)

Over time a varicocele can impair testicular growth or cause the affected testicle to become smaller and softer than the other.

8. Swelling that changes through the day

The scrotum may look or feel more swollen in the evening and return closer to normal after a night of rest.

9. Fertility problems

Varicoceles are the most common correctable cause of male infertility. They can lower sperm count, motility, and quality, so an abnormal semen analysis is sometimes the first clue.

10. Usually painless in the early stages

Importantly, many varicoceles cause no pain at all early on and are found incidentally. A painless varicocele can still affect fertility, which is why evaluation matters even without discomfort.

When it is not a varicocele

Several other conditions can cause scrotal swelling or discomfort and should be ruled out: a hydrocele (fluid around the testicle), an inguinal hernia, epididymitis (inflammation, usually with tenderness and sometimes fever), or a spermatocele (a cyst). Sudden, severe testicular pain is a medical emergency and needs immediate care. Any new scrotal lump should be examined by a physician to exclude other causes.

How a varicocele is diagnosed

Diagnosis begins with a physical examination while standing and during a Valsalva maneuver (bearing down), which makes the veins easier to feel. The finding is confirmed with a scrotal Doppler ultrasound, a painless scan that measures the size of the veins and detects reflux (backward blood flow). This same imaging helps grade the varicocele and plan treatment.

Varicocele treatment options

Not every varicocele needs treatment — many are simply monitored. Treatment is considered when there is persistent pain, testicular shrinkage, or fertility concerns. The two main options are surgery (varicocelectomy) and varicocele embolization, a minimally invasive, image-guided procedure performed by an interventional radiologist through a tiny catheter, with no surgical incision and a fast recovery. Read our full guide to varicocele treatment in Israel — embolization vs surgery to compare the approaches, or contact the clinic to arrange an evaluation with Dr. Shimon Aronhime.

Frequently asked questions

Is a varicocele dangerous? A varicocele itself is not life-threatening, but it can affect fertility and testicular development, so persistent or fertility-related cases should be evaluated.

Does a varicocele affect fertility? It can. Varicoceles are the most common correctable cause of male infertility and may reduce sperm count and quality; treatment often improves semen parameters.

Medically reviewed by Dr. Shimon Aronhime, MD, Interventional Radiologist and Endovascular Surgeon.

Israel Vein Center — Lilienblum 17, Tel Aviv · Shamir Medical Center, Beer Yaakov · Phone: 073-3744040