Most aches, lumps and changes in the body are not cancer. But a handful of warning signs, when they persist, are worth taking seriously — because catching cancer early is the single biggest factor in treating it successfully. Here are the signs you should never ignore.
Warning signs worth checking
See a doctor if any of these persist for more than two to three weeks:
- A lump anywhere — breast, neck, armpit, testis, or a deep or growing lump under the skin
- A sore, ulcer or patch (especially in the mouth) that does not heal
- Unexplained weight loss or persistent fatigue
- A change in bowel or bladder habits, or blood in stool or urine
- A persistent cough, hoarseness, or difficulty swallowing
- Unusual bleeding — between periods, after menopause, or when coughing
- A change in a mole’s size, shape or colour
- Night sweats and fevers without an obvious cause
The point of knowing the warning signs is not to worry — it is to shorten the gap between ‘something is not right’ and ‘let me get this checked,’ because that gap is where early cancers are lost.
What these signs usually mean
Reassuringly, most of these symptoms turn out to have harmless causes. But because a few do not, they deserve evaluation rather than guesswork. Depending on the sign, that may mean seeing a specialist — for example our breast, lung, colorectal, stomach or head and neck teams — and possibly a biopsy, explained in our guide on reading your biopsy report. A deep or growing lump in particular should be assessed before removal, as our sarcoma guide explains, and a persistent cough in a non-smoker is covered in our post on lung cancer in non-smokers.
Frequently asked questions
Does having a symptom mean I have cancer?
Usually not — most of these symptoms have harmless causes. But persistent ones should be checked.
How long should I wait before seeing a doctor?
If a warning sign lasts more than two to three weeks, get it evaluated.
Which doctor should I see?
Start with your physician, who can refer you to the right specialist. You can also share reports for a specialist opinion.
Are painless lumps safe?
Not necessarily — many early cancers are painless. Persistent lumps should be assessed.
Related reading: Understanding Your Biopsy Report · Sarcoma: Why Diagnosis Takes Months · Lung Cancer in Non-Smokers · Second Opinion for Cancer · Breast Cancer Specialist · Lung Cancer Specialist · Patient Support
Reviewed by Dr. Harish Kancharla
DM (Medical Oncology), AIIMS, New Delhi · MD (Internal Medicine), PGIMER, Chandigarh
Senior Consultant – Medical Oncology & Hemato-Oncology, Yashoda Hospitals, Somajiguda, Hyderabad
Telangana State Medical Council Registration No. 77186
Last reviewed: August 2026
This article is general information, not personal medical advice. Cancer decisions depend on your individual diagnosis, stage, test results and overall health. Please see our Medical Disclaimer.