For Zoë Armstrong, seeing the words “endometriosis” on an ultrasound report was an emotional moment.

After years of living with severe pain and making repeated visits to doctors, Armstrong finally had an explanation for what she had been experiencing. She broke down in tears while speaking to her mother, relieved to finally see her symptoms validated.

Her experience reflects a problem faced by millions of people with endometriosis. According to the American College of Obstetricians and Gynecologists, patients can wait 10 years or more from the onset of symptoms before receiving a diagnosis.

Endometriosis affects about one in 10 women worldwide. It occurs when tissue similar to the lining of the uterus grows elsewhere in the body, often causing severe pain and other complications.

Severe pain and a wide range of symptoms

Endometriosis is considered a chronic inflammatory disease, although its exact cause remains unknown. Genetics may also contribute to the condition.

The symptoms vary depending on where the tissue grows and how extensive the disease is. It commonly affects the ovaries, bladder and bowel, but can occasionally occur outside the pelvic region.

Severe pain during menstruation, sexual intercourse or bowel movements is among the most common symptoms. Patients may also experience bloating, fatigue and infertility.

Dr Drorit Or of Mount Sinai West in New York said the pain can be so severe that some patients are unable to attend school or work and may spend days in bed.

Armstrong began experiencing symptoms at 11. She had stabbing pain on the left side of her body and frequently visited her school nurse. Over time, she developed severe pain, nausea, heavy menstrual bleeding, acne and ruptured ovarian cysts.

After she got married, the pain became more frequent and intense.

Why diagnosis can take years

Armstrong was eventually diagnosed at 29 by a doctor who also had endometriosis.

An ultrasound detected an endometrioma, a type of cyst associated with the disease. After searching for the term online, Armstrong began to understand what might have been behind her years of symptoms. Surgery later confirmed the diagnosis.

Experts say several factors contribute to delayed diagnosis. Severe menstrual pain is often dismissed as normal, while symptoms can also resemble those of other conditions.

Dr Megan Billow of the Cleveland Clinic said some healthcare providers may not have enough experience or expertise to recognise endometriosis.

Doctors recommend that patients keep a record of their symptoms, including when the pain occurs, where it is located and how severe it becomes. Such information can help doctors identify patterns and determine whether endometriosis could be responsible.

Patients can also ask their doctors directly whether endometriosis may be behind their symptoms.

New tests could speed up diagnosis

New diagnostic tests are offering hope for earlier detection, although they have not yet been approved by the US Food and Drug Administration.

One of them, EndoSure, takes about 30 minutes and measures electrical signals in the gut through sensors placed on the abdomen. The results are then provided to the doctor.

Another test, Endotest, analyses saliva samples for microRNAs that may indicate endometriosis. Results are generally available within two to three weeks.

In the UK, health advisers have issued draft guidance recommending that both tests be used by the National Health Service for three years while more evidence is collected on their effectiveness. The goal is to help shorten diagnosis times, particularly in primary care.

Dr Mark Noar, founder of Maryland-based EndoSure, said the company is preparing an application to the FDA seeking approval for the test as a diagnostic aid.

French company Ziwig, meanwhile, is working to make Endotest available in the US through a pathway that allows certain laboratory-developed tests to be offered by certified laboratories without FDA approval.

Dr Andrew Spiers of Ziwig said the tests should be viewed as an important starting point rather than replacements for existing diagnostic methods. If doctors suspect endometriosis, patients may still need imaging and further examinations.

US doctors say the new tests could become useful additions to current diagnostic methods, but they are unlikely to solve the problem on their own. They also cannot address the long-standing tendency to dismiss severe menstrual pain as something people simply have to endure.

Treatment can help manage the condition

Once endometriosis is diagnosed, patients can work with their doctors to develop a treatment plan based on their symptoms and individual needs.

Treatment may include painkillers such as ibuprofen and prescription medicines specifically used to manage endometriosis. Hormonal treatments, including birth control pills, progestin therapy and medicines that temporarily stop menstruation, may also help control symptoms.

Surgery may be recommended in some cases. People with severe disease may require more extensive procedures, including a hysterectomy.

Armstrong underwent excision surgery to remove endometriosis lesions and scar tissue. She continues to receive regular care, including pelvic floor therapy and treatment for related health problems.

She now visits middle and high schools across New York City with the Endometriosis Foundation to raise awareness about endometriosis and other women’s health issues.

Armstrong believes young people need better information about the warning signs and when to seek medical help.

Dr Or said that although endometriosis can be difficult to diagnose and manage, patients should know that treatment and support are available.

Severe menstrual pain should not simply be accepted as a normal part of life, she said. With appropriate care, many people with endometriosis can manage the condition and live healthy, fulfilling lives.