What Is a Urachal Cyst?

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A urachal cyst is a sac of tissue and fluid between the bladder and the belly button (umbilicus). The cyst forms in the remnants of the urachus, a structure normally present in a fetus that usually closes up before birth. In some infants, the closure doesn't occur, causing a urachal cyst or sinus to form.

People can live comfortably with a urachal cyst their entire life without realizing it, as it usually doesn't cause any problems. However, drainage from the cyst can cause discomfort or other symptoms. The cyst can also get infected, a serious condition that needs immediate medical treatment.

This article covers the causes and symptoms of urachal cysts. It also discusses how urachal cysts are diagnosed and treated.

Infected Urachal Cyst Symptoms

Verywell / Laura Porter


Having a urachal cyst does not mean you will have symptoms. Urachal cysts or abscesses usually only cause symptoms if they become infected.

Symptoms of an infected urachal cyst include:

  • Abdominal pain
  • Fever
  • Abdominal masses
  • Pain or burning with urination
  • Frequent urinary tract infections
  • Blood in the urine

A severe urachal cyst infection can cause more widespread symptoms, such as abdominal redness and swelling, extreme fatigue, vomiting, and intense abdominal pain.

Rarely, urachal cysts allow urine to drain out of the belly button. In newborns, the drainage is usually caused by a problem in the cavity that connects the bladder and the belly button (urachal sinus). It can lead to poor healing of the umbilical cord after birth.

Drainage from a urachal cyst causes a constantly moist belly button, with urine coming from the navel. If not frequently cleaned, skin reddening and a foul odor may develop.

If you are experiencing symptoms of an infected urachal cyst, you'll need to be evaluated by a medical professional. Without treatment, infected cysts can cause serious health complications.


In the first trimester of pregnancy, the urachus is a channel between the fetus's bladder and umbilical cord that allows urine to drain from the fetus.

By the third trimester, the urachal channel seals off and becomes the medial umbilical ligament, a cord that extends from the pelvis to the top of the bladder. If the urachus remains open, its remnants can form a urachal cyst.

Urachal abnormalities are uncommon. They are usually discovered incidentally during imaging scans and autopsies. They're twice as likely to be found in men than women.

The exact cause of urachal abnormalities is unknown, but it's likely that many factors contribute to their development.

Urachal cysts are a congenital condition (present at birth), so there could be a genetic component. Some research has also suggested the cysts arise when the urachal area does not fully develop.

Several types of urachal abnormalities can cause symptoms after birth, including:

  • Patent urachus: A defect in which the urachus does not close off, leaving an opening between the bladder and belly button. Urine leaking from the navel is commonly seen in cases of a patent urachus.
  • Urachal sinus: A defect in which the urachus closes off near the bladder but remains open closer to the navel. A urachal sinus can cause fluid leakage from the navel or abdominal pain.
  • Diverticulum: The rarest type of urachal defect, in which the urachus does not seal off closer to the bladder. Diverticula commonly result in urinary tract infections.

Any type of urachal defect can become infected. Urachal cyst infections are most commonly seen in children between the ages of 2 and 4 years old.


Complications that arise from urachal cysts are typically related to infection. Bacterial infections are most common, and are usually caused by Staphylococcus aureus.

If an infected urachal cyst is not caught early, the infected cyst can pierce the bladder or peritoneal cavity, the space in the abdomen that contains the intestines, stomach, and liver.

Infected material from the cyst can then migrate into the bladder or peritoneal cavity. This can lead to a life-threatening condition called peritonitis, in which the lining of the abdomen and abdominal organs, known as the peritoneum, becomes infected and inflamed.

An infected urachal cyst can also lead to what's known as an enteric fistula, in which an abnormal connection forms between the cyst and nearby organs or structures. This complication is rare but life-threatening.

In addition to infection, there is also a small chance that a urachal cyst can become malignant (cancerous), resulting in urachal cancer. Urachal cancer is very rare form of bladder cancer, but it is highly aggressive.


The presence of a urachal cyst is confirmed through imaging techniques like ultrasounds, magnetic resonance imaging (MRI), and computed tomography (CT) scans. These scans allow healthcare providers to determine whether a cyst is present and problematic.

If your healthcare provider confirms the presence of a urachal cyst and you have symptoms of an infection, you will need further medical care. Your healthcare provider will ask you about your medical history, perform a physical exam, and may order lab tests before prescribing treatment.


If you have a urachal cyst that isn't causing symptoms, you don't have to take any specific action. Treatment would only be urgent if the cyst becomes infected.

In this case, antibiotics are required. Most urachal cyst infections can be treated with medications you take by mouth (oral antibiotics). However, if the infection is severe, you may need to get antibiotics through a vein in your arm (intravenous).

Sometimes, an infected urachal cyst needs to be removed surgically. Surgery may be recommended if the cyst causes excessive draining, irritation, discomfort, and/or repeated infection.

Removing the urachal cyst prevents future infections and reduces the risk of urachal cancer.

Similarly, a draining urachal sinus can be removed and closed off (excised) through a small incision of the belly button or with laparoscopic surgery.

Rarely, there have been cases where urachal abnormalities resolved spontaneously without treatment. Since this outcome is not as likely and urachal cysts can cause problems, you should discuss the best course of treatment for your situation with your healthcare provider.


A urachal cyst forms between the belly button and bladder when the fetal urachus fails to seal before birth. Many people go their whole lives without knowing they have a urachal cyst, since the abnormalities don't usually cause symptoms.

Occasionally, urachal cysts can lead to life-threatening complications, like bacterial infection, which needs to be treated with antibiotics. Much more rarely, a urachal cyst can lead to urachal cancer. Urachal cyst excision (surgical removal) reduces the risk of these complications.

A Word From Verywell

If you are experiencing symptoms of an infected urachal cyst, including sudden or severe abdominal pain, it's important to seek immediate medical care. Even if you don't have an infected urachal cyst, your symptoms could be related to another serious medical condition like appendicitis, which causes similar symptoms. Either way, a proper diagnosis and treatment is critical and can prevent life-threatening complications later on.

11 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Kwok CM. Infected urachal cyst in an adult: A laparascopic approach. Case Rep Gastroenterol. 2016;10(1):269–274. doi:10.1159/000446642

  2. Elkbuli A, Kinslow K, Ehrhardt J, et al. Surgical management for an infected urachal cyst in an adult: Case report and literature review. Int J Surg Case Rep. 2019 Mar;57(1):130–133. doi:10.1016/j.ijscr.2019.03.041

  3. Shan T, Lung-Huang L, Shih-Pin H. An infected urachal cyst presenting as acute abdominal pain in a child. Medicine. 2020 Jan;99(5):e18884. doi:10.1097/MD.0000000000018884

  4. Jayakumar S, Darlington D. Acute presentation of urachal cyst: A case report. Cureus. 2020 May;12(5):e8220. doi:10.7759/cureus.8220

  5. Danial AK, Tarabishi AS, Aldakhil A, et al. Acute abdomen due to an infected urachal cyst in a 5-year-old female: case report. J Surg Case Rep. 2019 May;2019(5):1-4. doi:10.1093/jscr/rjz156

  6. University of California, San Francisco Medical Center - Department Of Urology. Urachal abnormalities.

  7. Lucerna A, Lee J, Espinosa J, Hertz R, Scali V. An adult with a remnant urachus anomaly diagnosed in the emergency departmentCase Reports in Emergency Medicine. 2018;2018:1-3. doi:10.1155/2018/6051871

  8. Wilson AL, Gandhi J, Seyam O, et al. Urachal anomalies: A review of pathological conditions, diagnosis, and managementTranslational Research in Anatomy. 2019;16:100041. doi:10.1016/j.tria.2019.100041

  9. Loizza D, Pandolfo S, Crocerossa F, et al. Current management of urachal carcinoma: An evidence-based guide for clinical practice. Eur Urol Open Sci. 2022 May;39(1):1-6. doi:10.1016/j.euros.2022.02.009

  10. Rhudd A, Moghul M, Nair G, McDonald J. Malignant transformation of a urachal cyst—a case report and literature review. 2018;2018(3). doi:10.1093/jscr/rjy056

  11. Bagnara V, Antoci S, Bonforte S, et al. Clinical considerations, management and treatment of fever of unknown origin caused by urachal cyst: a case reportJ Med Case Rep. 2014;8(1). doi:10.1186/1752-1947-8-106

Additional Reading

By Brittany Ferri
Brittany Ferri, MS, OTR-L, CCTP, is an occupational therapist, consultant, and author specializing in psychosocial rehab.