7 silent cancer symptoms everybody needs to know about

Not all cancer symptoms are obvious (Alamy/PA)
Not all cancer symptoms are obvious (Alamy/PA)

Finding a lump, abnormal bleeding, or losing weight for no reason are well-known possible signs of cancer. But there are many other potential symptoms that may surprise you.

To mark World Cancer Day on February 4, Cancer Research UK (CRUK; highlights the importance of getting anything unusual checked by a doctor.

“There are more than 200 types of cancer, with lots of possible symptoms,” says Dr Julie Sharp, head of health and patient information at CRUK. “It’s impossible to know them all, which is why it’s important to seek your doctor’s advice.

“Catching cancer early means treatment is more likely to be successful,” Sharp adds. “If you notice unusual or persistent changes to your health, make an appointment with your GP as soon as possible.”

However, there are some potential cancer warning signs that you might not necessarily link to the disease.

Dr Alexandra Oliver, associate clinical director at Bupa Health Clinics (, says: “Many people are aware of the obvious signs of cancer, such as a new lump or a change to a mole. However, other symptoms may be less obvious, but it’s still important that people are aware of them.

“In most cases, it’s likely to be nothing serious, but making sure you get checked out by a doctor if you have any symptoms, particularly persistent ones, is essential.”

These are some of the less obvious possible signs of cancer…

1. Fatigue

It’s normal to feel tired sometimes, and a good night’s sleep and some rest is usually all that’s needed to feel brighter. However, Oliver says: “There are many medical conditions that can cause fatigue, but it could be a symptom of cancer. If you’ve noticed you’re feeling constantly fatigued and it’s preventing you from working, or carrying out your daily activities, you should mention this to your GP, who may consider further investigations.”

2. Night sweats

Night sweats can sometimes be normal, especially for women who are on their period or going through the menopause, says Oliver. However, she points out that some cancers can be associated with night sweats, including bone cancer, leukaemia and liver cancer. “If you’re experiencing regular, heavy night sweats, speak to a doctor,” she advises.

3. Persistent indigestion and heartburn

Indigestion and heartburn can be a result of eating certain foods, such as spicy or fatty dishes. They can also be associated with being overweight, a smoker or pregnant, says Oliver. However, it’s important to get it checked, in case anything else is going on.

“Occasional acid reflux can be normal,” she explains, “but when it doesn’t go away, it can result from gastroesophageal reflux disease, a hiatus hernia, oesophageal cancer or stomach cancer. If you’re experiencing persistent indigestion or heartburn, speak to a doctor, who’ll be able to investigate the cause and discuss treatment options.”

4. Long-lasting mouth ulcers

Mouth ulcers are very common and can be caused by many things, including poorly fitting dentures, erupting wisdom teeth, infections, medication, dietary deficiencies or damage caused while brushing, says Susie Lloyd, a dentist at Bupa Dental Care (

But she warns: “If you have a mouth ulcer that isn’t healing, it’s time to seek help. Ulceration that hasn’t healed after three weeks could signify something more serious, such as mouth cancer. It’s important to speak to your dentist, who can refer you to a specialist for further investigation.”

5. Persistent hoarseness

Hoarseness is a common condition that is usually linked with a dry or sore throat, but it can also be connected to overuse of the voice.

Symptoms usually stem from inflammation in the throat (laryngitis), but Oliver says: “Persistent hoarseness, which lasts for 10 days or more, should be checked by a medical professional, as it could be a serious underlying medical condition, such as laryngeal cancer.”

6. Persistent bloating

If you’ve been feeling bloated most days for the past few weeks, speak to your GP, Oliver advises. She points out that bloating isn’t usually anything serious, and could be caused by a gastrointestinal condition, such as irritable bowel syndrome (IBS). “But you should get this checked out if it’s something you haven’t experienced before,” she says.

A doctor will feel your tummy and ask about your symptoms and general health. “While it’s unlikely, it could be a sign of gynaecological or bowel cancer,” says Oliver.

7. Persistent cough

Coughs are very common and usually go away on their own over time. But Oliver says if a cough persists for more than three weeks, it’s definitely worth getting it checked out by your GP. “Often, a persistent cough will be linked to heartburn or allergies,” she says, “but there’s a small chance it could be linked to lung cancer.”