The cancer specialist has listed symptoms to look for and how to know when to ask for adviceNeil Shaw Assistant Editor (Money and Lifestyle)10:03, 20 Jul 2026Updated 10:04, 20 Jul 2026Persistent tiredness, unexplained weight loss or a cough that refuses to go away are often blamed on getting older, a busy lifestyle or a lingering virus. But according to a cancer specialist, they are among the symptoms that people too often ignore for months before finally seeking medical advice.‌While most ongoing symptoms will have a harmless explanation, doctors say it’s important not to dismiss changes that are persistent, unexplained or noticeably different from what’s normal for you. Knowing when something deserves further investigation can make all the difference.‌The warning comes as cancer cases in the UK have reached a record high. More than 403,000 people are now diagnosed every year - around 1,100 every day, or one person every 80 seconds - according to Cancer Research UK’s latest figures.‌Dr Jiri Kubes, radiation oncologist and Medical Director at Proton Therapy Center, said one of the biggest misconceptions is that cancer always causes severe pain or dramatic symptoms from the outset. In reality, early warning signs are often subtle and can easily be mistaken for far more common conditions.He said: “One symptom on its own rarely points to cancer, and the vast majority of people experiencing these symptoms will not have cancer. The important thing is persistence. If something continues for several weeks, keeps returning or simply doesn’t feel right for you, it’s always worth getting checked rather than assuming it will eventually go away.”‌Persistent fatigueEveryone feels tired after a busy week or a few poor nights’ sleep, but persistent fatigue that doesn’t improve with rest is something doctors take more seriously. It can affect your ability to work, exercise or carry out everyday activities and often feels very different from ordinary tiredness.Dr Kubes said: “Cancer-related fatigue is often described as an overwhelming exhaustion that doesn’t improve with sleep. There are many possible explanations, including anaemia, thyroid disorders, infections and poor sleep, but persistent fatigue should always be discussed with your GP if it isn’t improving.”‌A cough that won’t go awayMost coughs caused by viral infections settle within a few weeks, but one that persists or gradually worsens should not simply be ignored. This is particularly true if it’s accompanied by breathlessness, chest pain or coughing up blood.“A persistent cough doesn’t automatically mean cancer,” Dr Kubes said. “In fact, there are many more common causes. However, if it continues beyond a few weeks or behaves differently from a typical cough, it’s sensible to have it assessed.”Unexplained weight lossLosing weight without changing your diet or exercise routine can sometimes be an early sign that something isn’t quite right. Although many conditions can cause unexpected weight loss, it’s one of the symptoms doctors always want to investigate.Article continues belowDr Kubes said: “If you’re losing weight despite eating normally and haven’t intentionally changed your lifestyle, it’s important to understand why. Often there will be another explanation, but it’s not something that should simply be overlooked.”He added: “One of the biggest mistakes people make is waiting for symptoms to become severe before seeking help. Cancer doesn’t always announce itself dramatically, and many of the early warning signs are vague and easily explained by more common conditions.“The important thing isn’t to become anxious about every cough or ache, but to pay attention to symptoms that persist, keep returning or simply don’t feel normal for you. In many cases they’ll turn out to have a harmless explanation, but if something more serious is going on, getting it checked early gives us the best possible chance of diagnosing and treating it successfully.”