The trigone is the neck of the bladder. It’s a triangular piece of tissue located in the lower part of your bladder. It’s near the opening of your urethra, the duct that carries urine from your bladder outside of your body. When this area becomes inflamed, it’s known as trigonitis.

However, trigonitis isn’t always the result of inflammation. Sometimes it’s due to benign cellular changes in the trigone. Medically, these changes are called nonkeratinizing squamous metaplasia. This results in a condition called pseudomembranous trigonitis. These changes occur due to hormonal imbalances, particularly the female hormones estrogen and progesterone.

Symptoms of trigonitis aren’t unlike those for other bladder issues. They include:

Trigonitis has a variety of causes. Some common ones are:

  • Long-term use of a catheter. A catheter is a hollow tube inserted into your bladder to drain urine. It’s often used after surgery, after spinal injuries, or when nerves in your bladder that signal emptying are injured or misfiring. The longer a catheter stays in place, however, the higher the risk for irritation and inflammation. This increases the chances of trigonitis. If you have a catheter, talk to your doctor about proper care.
  • Recurrent urinary tract infections (UTIs). Frequent infections can irritate the trigone, leading to chronic inflammation and trigonitis.
  • Hormonal imbalances. It’s thought that female hormones estrogen and progesterone may play a role in the cellular changes that occur with pseudomembranous trigonitis. The majority of people with trigonitis are women of childbearing age as well as men undergoing hormone therapy for things like prostate cancer. According to research, pseudomembranous trigonitis occurs in 40 percent of adult women — but fewer than 5 percent of men.

Trigonitis is almost impossible to distinguish from ordinary UTIs based on symptoms. And while a urinalysis can detect bacteria in your urine, it can’t tell you whether the trigone is inflamed or irritated.

To confirm a diagnosis of trigonitis, your doctor will perform a cystoscopy. This procedure uses a cystoscope, which is a thin, flexible tube equipped with a light and lens. It’s inserted into your urethra and bladder. You may receive a local anesthetic applied to the urethra before the procedure to numb the area.

The instrument allows your doctor to view the inside lining of the urethra and bladder and look for signs of trigonitis. These include inflammation of the trigone and a kind of cobblestone pattern to the tissue lining it.

How your trigonitis is treated will depend on your symptoms. For example, you may be prescribed:

  • antibiotics if you have bacteria in your urine
  • low-dose antidepressants, which can help control pain
  • muscle relaxers to relieve bladder spasms
  • anti-inflammatories

Your doctor may also advise a cystoscopy with fulguration (CFT). This is a procedure done on an outpatient basis under anesthesia. It uses a cystoscope or a urethroscope to cauterize — or burn — inflamed tissue.

CFT works under the theory that as damaged tissue dies, it’s replaced by healthy tissue. In one study, 76 percent of women undergoing CFT had resolution of their trigonitis.

Interstitial cystitis (IC) — also called painful bladder syndrome — is a chronic condition that produces intense pain and inflammation in and above the bladder.

How IC is caused isn’t fully known. One theory is that a defect in the mucus that lines the bladder wall allows toxic substances from urine to irritate and inflame the bladder. This produces pain and a frequent urge to urinate. IC affects 1 to 2 million Americans. An overwhelming majority of them are women.

While they share some of the same symptoms, trigonitis differs from IC in several ways:

  • The inflammation that occurs with trigonitis is only seen in the trigone region of the bladder. IC can cause inflammation throughout the bladder.
  • Pain from trigonitis is felt deep into the pelvis, radiating to the urethra. IC is generally felt in the lower abdomen.
  • According to research published in the African Journal of Urology, trigonitis is more likely than IC to produce pain upon passing urine.

Trigonitis is common in adult women. While it can produce some painful and inconvenient symptoms, it does respond well to the right treatment.

If you think you have trigonitis or any other bladder issues, see your doctor or urologist to discuss your symptoms, get a thorough examination, and receive the appropriate treatment.