A horseshoe kidney is a congenital condition that causes the kidneys to join and form a horseshoe shape. Healthcare providers don’t know what causes it. But common complications include frequent UTIs and kidney stones. Medications can treat infections, and surgery can relieve obstructions or remove kidney stones.

A horseshoe kidney can develop on its own. But it may also often occur alongside other conditions, including:

Chromosomal conditions

Down syndrome.
Turner syndrome.
Pautau syndrome (trisomy 13).
Edwards syndrome (trisomy 18).
Nonchromosomal conditions

Ellis-van Creveld (EVC) syndrome.
Fanconi anemia (FA).
Goltz syndrome.
Kabuki syndrome.
Pallister-Hall syndrome.
VATER syndrome.

Most people have no symptoms of a horseshoe kidney. If you do, they may include:

Nausea and vomiting.
Frequent urinary tract infections (UTIs), which may also cause pain when you pee (dysuria) along with a fever.
Kidney stones, which may cause abdominal (belly) pain, blood in your pee (hematuria) and pain when you pee.