Noida, Delhi oncologist warns 'persistent cough is not normal'; shares early signs of lung cancer you should not ignore

A cough that lingers for weeks is never normal. Oncologist Dr Manish Sahni explains the early signs of lung cancer and why timely evaluation is crucial.

A cough that continues for weeks despite rest, routine medication, and familiar home remedies is often the body’s way of indicating that something deeper may be happening inside the lungs. A persistent cough is rarely just a leftover infection or a seasonal reaction, and when it lingers without a clear reason, it becomes a clinical sign that deserves attention.

In many early-stage lung cancer cases, this cough appears long before any noticeable pain or breathlessness, which is why people tend to brush it aside. In an interview with HT Lifestyle, Dr Manish Sahni, surgical oncologist and robotic surgeon, Kailash Hospital, Noida and Delhi, shares why a persistent cough is never “normal” and lists the early signs of lung cancer to watch for.

What lung-cancer coughs look like

Sharing key symptoms, Dr Sahni says, “A cough linked to lung cancer behaves differently from one that follows a cold or a viral illness. It often carries on for more than three weeks, does not respond to usual symptomatic treatment, and may slowly become deeper or more forceful as the tumour irritates the airway lining. Some individuals notice blood tinges in the mucus or a change in their voice. These shifts occur because an early tumour can alter the airflow pathways or create subtle pressure inside the lungs, triggering irritation that results in a steady cough.”

Pollution is changing who gets diagnosed

According to Dr Sahni, smoking still remains a major contributor, but it’s no longer the only one. “There is also a visible change in the profile of patients being diagnosed today. Smoking remains a major risk factor, yet a growing number of cases are now being detected in individuals with no history of tobacco use. Long-term exposure to polluted air is emerging as an important contributor.

Many significant factors contribute to lung cancer risks that are frequently overlooked ((Shutterstock))

He adds, “Fine particulate matter and toxic gases can travel deep into the lung tissue, causing persistent inflammation that, over time, may alter the genetic behaviour of lung cells. This helps explain why people living in severely polluted cities are reporting symptoms earlier, even without traditional risk factors.”

The subtle signals most people overlook

He also highlights that lung cancer symptoms are often mistaken for everyday fatigue or minor infections: “The early phase of lung cancer often blends into everyday life. Unexplained tiredness, a sense of heaviness in the chest, mild breathlessness during routine tasks, frequent throat irritation or a sudden drop in appetite are frequently mistaken for minor health fluctuations.”

“Tuberculosis is a major public health challenge in India, and its symptoms mimic early signs of lung cancer, making it one of the important factors for delayed diagnosis. Some individuals also experience recurrent chest infections because tumour-related obstruction can prevent air from moving freely in the affected area,” says Sahni.

Ending with a reminder, Dr Sahni emphasises, “Lung cancer tends to progress quietly, which is why delays in seeking care remain common. Any cough that persists beyond a few weeks, particularly in high-pollution environments or in people with a family predisposition, should be evaluated. With timely diagnosis supported by advanced imaging and precise treatment options, outcomes can improve considerably. Recognising the earliest signs and responding without delay can make a meaningful difference.”

Note to readers: This article is for informational purposes only and not a substitute for professional medical advice. Always seek the advice of your doctor with any questions about a medical condition.