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What Are the Symptoms of Nutcracker Syndrome?

LJ Dong, NKR Nutcracker Donor Mentor

Nutcracker syndrome is a rare condition that happens when the left renal vein—which carries blood from your kidney—gets compressed, often between the aorta and another nearby artery. This pressure can affect blood flow and lead to a range of symptoms. Because the signs can vary from person to person, it’s often difficult to diagnose without proper testing.

Here are the most common symptoms to watch for:

1. Flank or Abdominal Pain

Many people experience sharp pains or a persistent ache on the left side of the abdomen or in the lower back (flank area). The pain may be constant or come and go.

2. Blood in the Urine (Hematuria)

One of the more common symptoms of Nutcracker Syndrome is blood in the urine. It can be visible (red or pink urine, called gross hematuria), or only detectable in lab tests (microscopic hematuria).

3. Pelvic or Lower Abdominal Pressure

Compression of the vein can lead to blood flow backup, causing pelvic congestion and a feeling of heaviness or fullness.

4. Protein in the Urine (Proteinuria)

Nutcracker Syndrome can also cause protein in the urine, which is usually discovered during routine tests.

5. Varicocele in Males

Men affected by Nutcracker Syndrome may develop a varicocele—enlarged veins in the scrotum—usually on the left side.

6. Pelvic Congestion in Females

Women with Nutcracker Syndrome may experience pelvic pain, pain during or after intercourse, or varicose veins in the pelvis or thighs.

7. Fatigue or Dizziness

If blood loss from hematuria is significant, it can lead to low iron levels or anemia, which may cause fatigue, lightheadedness, or weakness.

When to Talk to a Doctor

Because Nutcracker Syndrome shares symptoms with other kidney and urologic conditions, it’s important to see a healthcare provider if you notice any of the symptoms listed above. A doctor may use imaging tests—such as ultrasound, CT, or MRI—to confirm the diagnosis. Left untreated, Nutcracker Syndrome can affect kidney function and quality of life. The good news is that there are both conservative and surgical treatment options, depending on severity. Your doctor can help you decide which treatment is right for you.

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