New Delhi: On World Ankylosing Spondylitis (AS) Day, medical experts flagged the condition as widely underdiagnosed in India, warning that it is often mistaken for routine back pain despite primarily affecting young adults in their most productive years.Specialists said lakhs of patients face an average diagnostic delay of nearly seven years, during which the disease can silently progress, affecting the spine, joints and posture, and in some cases even organs such as the eyes. What often begins as mild lower back discomfort can gradually turn debilitating if left untreated.Doctors said one of the biggest challenges lies in distinguishing ankylosing spondylitis from mechanical back pain. “What misleads both patients and general physicians is that the pain feels ordinary. But inflammatory back pain follows a distinct pattern—marked stiffness in the early morning or after prolonged rest, which improves with physical activity,” said Dr Arvind Mehra, senior director and head of orthopaedics at Paras Health, Gurugram.According to Dr Mehra, India has an estimated 16.5 lakh AS patients, many of whom remain undiagnosed for years. “The spine does not have to fuse and mobility does not have to be lost—but that depends entirely on early diagnosis and timely intervention,” he said.Rohit Lamba, director of orthopaedics at Fortis Manesar, said AS typically begins early in life. “It often starts as lower back pain and stiffness in the late teens or twenties. Even MRIs can appear normal initially. Over time, however, the ligaments around the spine begin to calcify and fuse with the bones, making the spine increasingly stiff,” he said. In severe cases, he added, the spine may become completely rigid, affecting posture and vision, while some patients also develop hip arthritis.Lamba said diagnosis is largely clinical and supported by specific investigations. “If a young patient presents with persistent lower back pain and stiffness, blood tests such as HLA-B27 can support the diagnosis. Timely and appropriate intervention can significantly alter the course of the disease,” he noted.Dr Ashish Tomar, director of orthopaedics and minimally invasive spine surgery at Sarvodaya Hospital, stressed that AS is not merely a musculoskeletal disorder but an autoimmune disease. “It doesn’t announce itself clearly. By the time many patients seek medical care, damage to the spine has already begun,” he said.He added that the disease can extend beyond the spine. “AS may involve the chest, hips, shoulders and even the eyes. Persistent inflammatory back pain—especially pain in the gluteal region lasting more than three months—should not be dismissed and warrants further evaluation rather than just symptomatic pain relief.”Echoing the need for greater awareness, Dr Gaurav Bhardwaj of PSRI Hospital said the condition is not necessarily becoming more common but is being recognised more frequently. “With improved awareness and diagnostic tools, we are identifying cases earlier. However, sustained awareness is key to preventing irreversible damage,” he said.Doctors emphasised that early diagnosis, along with medication, physiotherapy and lifestyle measures such as regular exercise, yoga and swimming, can slow disease progression and enable patients to lead active, productive lives.