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Kidney differences from birth (single, horseshoe, or pelvic kidney)

Also called: Single kidney, horseshoe kidney, kidney differences from birth

Kidney shape or number differences, often found on ultrasound. Most people live normal lives.

CheckBlood pressure, urine

Overview

About 1 in 1,000 people are born with one kidney; a horseshoe kidney is joined at the bottom.

Most people never know until a scan.

Symptoms

Common signs:

  • Found on ultrasound

Less common

  • Kidney stones
  • UTIs

When to get medical care

Call 911This isn't an emergency by itself. Call 911 for trouble breathing, chest pain, or fainting.
Get care todayNew or worse symptoms, or symptoms with fever.
See a doctor soonSymptoms that last or keep coming back.

Causes

Development.

Does it spread or run in families?

  • It isn't contagious. You can't catch it from someone else.

Diagnosis

A clinician asks about your symptoms and may order tests.

The exam

A physical exam.

Tests

Tests, if needed:

  • Ultrasound:

Treatment

Treatment depends on the cause and how severe it is.

Self-care

  • Stay hydrated
  • Get yearly blood pressure and urine checks
  • Avoid NSAIDs when possible

Prevention

To lower your risk or prevent problems:

  • Stay hydrated

Which doctor treats this

  • Start with your primary care provider (family doctor or internist).
  • They may send you to a nephrologist (kidney doctor).

Living with it

Support groups and helplines

Children, pregnancy, and older adults

  • Athletes with one kidney: Ask about protective gear.

Pregnancy and breastfeeding

  • If you're pregnant or planning to be, tell your prenatal provider about this condition.
  • This condition needs closer checkups during pregnancy. Plan ahead with your doctor.
  • Don't start or stop any medicine on your own. Some are safe in pregnancy and some need to be changed.
  • Ask before taking any pain reliever. The FDA advises avoiding ibuprofen and naproxen after 20 weeks unless your doctor says to.
  • Breastfeeding: Most medicines are fine, but ask. The NIH LactMed database lists what's known about each one.

Outlook

Most live normal lives.

Getting ready for your visit

Bring a list of your symptoms and medicines.

What to bring

  • A list of your medicines and supplements
  • Notes on when symptoms started and what makes them better or worse

Questions to ask

  • What's causing this?
  • What treatment do you recommend?

Research studies

Research studies test new ways to find and treat health problems. Some are looking for volunteers. Talk with your doctor before joining one.

Search ClinicalTrials.gov for studies on Kidney differences from birth (single, horseshoe, or pelvic kidney)

Sources

Last updated 2026-11-12.