No symptom on its own shows that someone has cancer; only a doctor's examination and tests can make that clear [10]. The main warning signs are: a new lump or swelling, weight loss or weight gain for no known reason, a cough or hoarseness that does not go away, blood in your stool, urine or phlegm, a lasting change in bowel habits, trouble swallowing, a sore that does not heal, a new mole or a mole that has changed, bleeding or bruising for no known reason, fever or night sweats for no known reason, and severe tiredness that lasts [1]. Most of the time these symptoms have a simpler cause; but if they have not got better after a few weeks, see a doctor, and do not wait for pain, because cancer often does not cause pain [1].
Key points
- Most of these symptoms are not cancer. In a survey in England, more than half of people aged 50 and over had had one of these warning signs in the previous 3 months [6]. Of every 100 people who had bleeding from the back passage for the first time, about 2 were diagnosed with bowel cancer in the next 3 years [4].
- But do not ignore them. In the same survey, only 2 in every 100 people who had such a symptom had thought it might be cancer [6]. A symptom that is new, has lasted a few weeks, is getting worse or keeps coming back should be checked [1, 3].
- Early cancer often causes no pain and no symptoms; that is why screening (testing people who have no symptoms) matters for several common cancers [1, 9].
- Seeing a doctor early makes a difference: in a large study, for most symptoms more than half of patients were diagnosed before the cancer had spread to distant parts of the body [7]; and in breast, bowel, head and neck and testicular cancer and melanoma, a quicker diagnosis has been linked with better results [8].
Early signs of cancer: what are the warning signs?
Cancer can start anywhere in the body, and its symptoms depend on where it is. These are signs that different cancers may cause; but most of the time the same symptoms are due to other illnesses, injuries or benign (non-cancerous) lumps [1]. For each sign, also see the symptoms page for that cancer.
Changes in the breast
A lump or firm feeling in the breast or under the arm, a change in the nipple or discharge from it, or breast skin that has become red, scaly, dimpled or puckered [1]. Show a new breast lump to a doctor promptly, especially if you are 30 or older [2]. Read more: What are the symptoms of breast cancer? and I found a lump in my breast. What should I do?
A lump or swelling elsewhere in the body
A new lump or swelling in the neck, armpit, abdomen, groin or testicle [1]. Most lumps are not cancer, but a lump that has been there for a few weeks or is getting bigger should be examined [1, 2]. Show a doctor any change in the size, shape or firmness of a testicle, even if it is not painful [2]. See: swollen lymph nodes, symptoms of lymphoma, symptoms of testicular cancer and symptoms of thyroid cancer.
Unexplained weight loss
Losing weight without dieting or exercise, or losing your appetite [1, 2]. In a large study in England, about 1 in every 20 adults who had lost weight for no known reason was diagnosed with cancer in the next 6 months; the risk was higher in men aged 50 and over and women aged 60 and over [5]. Have unexplained weight loss checked promptly, especially if it comes with another symptom such as belly pain, loss of appetite or trouble swallowing [5]. See: unexplained weight loss, symptoms of pancreatic cancer and symptoms of stomach cancer.
A cough or hoarseness that does not go away
A cough or hoarseness that has not gone away after a few weeks, or blood in your phlegm [1]. In a large study, fewer than 1 in 10 people who coughed up blood for the first time were diagnosed with cancer of the lung or airways in the next 3 years [4]; so the cause is usually something else, but blood in the phlegm should always be checked. If you smoke or used to smoke, have an unexplained cough, shortness of breath or chest pain checked sooner [2]. See: symptoms of lung cancer and symptoms of throat cancer.
Blood in the stool or a change in bowel habits
Blood in your stool, or a change in bowel habits that does not go away, such as new constipation or diarrhoea [1]. Bleeding from the back passage usually has a simpler cause [4]; even so, it should be checked, especially after the age of 50 or if it comes with belly pain and weight loss [2]. See: Blood in your stool: piles or bowel cancer?, symptoms of bowel cancer and My faecal occult blood test was positive. What should I do?
Blood in the urine or problems passing urine
Blood in the urine, pain when passing urine, or difficulty passing urine [1]. Fewer than 1 in 10 people who had blood in their urine for the first time were diagnosed with cancer of the urinary tract in the next 3 years [4]; but blood in the urine should be checked promptly, especially after the age of 45 and when there is no urine infection [2]. See: symptoms of bladder cancer, symptoms of kidney cancer and symptoms of prostate cancer.
Trouble swallowing, indigestion or jaundice
Difficulty swallowing food, heartburn or indigestion that does not go away, belly pain, nausea and vomiting, changes in appetite, or yellowing of the skin and the whites of the eyes (jaundice) [1]. Show a doctor trouble swallowing promptly, at any age; UK national guidelines recommend a fast-track referral for it [2]. Indigestion or upper belly pain with weight loss after the age of 55 also needs a prompt check [2]. See: symptoms of oesophageal cancer, symptoms of stomach cancer and symptoms of liver cancer.
A sore or patch in the mouth that does not heal
A sore that does not heal, a white or red patch on the tongue or inside the mouth, or bleeding, pain or numbness of the lip or mouth [1]. A mouth ulcer that has lasted more than 3 weeks should be examined [2]. See: symptoms of mouth cancer.
A new mole or a change in the skin
A new mole, or a mole that has changed in size, shape or colour; a skin-coloured lump that bleeds or turns scaly; or a skin sore that does not heal [1, 2]. See: what a cancerous mole looks like and symptoms of skin cancer.
Unexplained bleeding or bruising
Bruising or bleeding for no known reason, or tiny red spots under the skin, especially together with paleness, tiredness or one infection after another [1, 2]. A doctor usually starts with a simple full blood count (CBC) [2]. In women, show a doctor any bleeding after the menopause promptly [2]. See: symptoms of leukaemia and symptoms of womb cancer.
Unexplained fever or night sweats, and swollen glands
Fever or night sweats with no known cause [1], especially together with swollen lymph nodes (glands) in the neck, armpit or groin, itching, shortness of breath or weight loss [2]. See: night sweats, fever and itching, swollen lymph nodes and symptoms of lymphoma.
Severe tiredness that lasts
New pain that does not go away
Pain with no known cause that does not go away, such as belly, chest or back pain, is one of the symptoms that people with cancer first went to their doctor with [7]. Lasting bone or back pain after the age of 60, or a fracture with no clear reason, is checked with blood tests for multiple myeloma [2]. See: symptoms of multiple myeloma.
Headaches, seizures or changes in vision
Headaches, seizures, changes in vision or hearing, or drooping of one side of the face [1]. A nerve problem that slowly gets worse, such as weakness or clumsiness, should be checked promptly, and the doctor may arrange a brain scan [2]. See: symptoms of a brain tumour.
How do you know if you have cancer?
You cannot tell from a symptom alone whether cancer is there or not; each of these symptoms has many other possible causes [1]. A doctor starts by listening to your story and examining you and, if needed, orders blood tests, scans or a biopsy. A blood test alone cannot confirm or rule out cancer for sure, and a biopsy is often the only way to know for certain [10]. Even among people whom a doctor refers for a fast check because cancer is suspected, most do not have cancer [3].
These three points help you know which symptoms to show a doctor sooner [1, 3]:
- It is new: you have not had anything like it before.
- It lasts: it has not got better after a few weeks or it keeps coming back.
- It is getting worse or comes with another symptom: for example, indigestion together with weight loss.
Read more: What is the difference between a benign and a malignant tumour? and Does a biopsy make cancer spread?
What does cancer feel like? Does cancer hurt?
Many people expect cancer to be painful; but cancer often causes no pain, especially at the start [1]. Many people feel nothing in particular and only notice a change: a lump that was not there before, a mole that has changed, or blood where there should be none. Some feel tired, lose their appetite or lose weight [1]. So do not wait for pain; if a symptom has lasted a few weeks, see a doctor [1].
Early cancer often has no symptoms: the role of screening
At the start, cancer is usually small and may cause no symptoms at all. Screening means testing healthy people who have no symptoms so that cancer, or changes that come before cancer, are found earlier, when treatment is easier [9]. These screening tests have been shown to work [9]:
- mammography for breast cancer (At what age should I start mammograms?)
- HPV testing and the Pap (smear) test for cervical cancer
- a stool test or colonoscopy for bowel cancer (At what age is a screening colonoscopy needed?)
- low-dose CT scans of the lungs for some current or former smokers
Which ones you need depends on your age, sex and family history: cancer screening. Screening does not replace paying attention to symptoms; if you have a symptom, do not wait for your next screening appointment, even if your last screening result was normal [2].
When should I contact a doctor?
Go to an emergency department the same day or call your local emergency number if you vomit blood or have black, tarry stools, cough up a lot of blood, become suddenly short of breath, or if your face suddenly droops on one side, an arm or leg suddenly becomes weak, or you have a seizure.
See a doctor within the next few days if [1, 2]:
- you have found a new lump in your breast, testicle, neck or anywhere else in your body
- food sticks when you swallow
- you have seen blood in your urine, phlegm or stool
- you have had bleeding after the menopause
- your skin or the whites of your eyes have turned yellow
- you have lost weight for no known reason
- you have bruising, tiny red spots under the skin or bleeding for no known reason
If any other symptom has not got better after a few weeks, such as a cough, hoarseness, a mouth ulcer, indigestion or a change in bowel habits, book an appointment [1]. If you have been checked but the symptom continues, gets worse or comes back, go back to the doctor [3].
Why does seeing a doctor early matter?
Some people fear that if their symptom turns out to be cancer, the disease must be advanced. But in a large study in England of nearly 8,000 patients, for most symptoms more than half of patients were diagnosed before the cancer had spread to distant parts of the body [7]. A breast lump, an abnormal mole, bleeding after the menopause and bleeding from the back passage were more often found at an earlier stage than the other symptoms [7].
In a review of 209 studies, a quicker diagnosis was linked with better results in breast, bowel, head and neck and testicular cancer and melanoma [8]. Cancer that is found early is often easier to treat [9].
One thing to do today: if you have a symptom, write down what it is, when it started and how often it happens, and take this note to your family doctor (GP). For other simple steps, read 5 simple steps to find cancer early.
Frequently asked questions
What are the signs of cancer in women?
As well as the signs above, these matter in women: changes in the breast, such as a lump, discharge or a change in the nipple, and changes in the breast skin [1]; bleeding after the menopause [2]; and bloating, feeling full quickly, belly or pelvic pain, or needing to pass urine more often, when these happen on most days and do not go away, especially after the age of 50 [2]. See: signs of cancer in women, symptoms of breast cancer, symptoms of ovarian cancer, symptoms of cervical cancer and symptoms of womb cancer.
What are the signs of cancer in men?
As well as the general signs, these matter in men: a painless swelling or a change in the shape or firmness of a testicle [2], and problems passing urine or blood in the urine [1, 2]. See: signs of cancer in men, symptoms of testicular cancer, symptoms of prostate cancer and symptoms of bladder cancer.
Does cancer make you tired?
Yes, sometimes. Severe tiredness that lasts is one of the signs of cancer [1], for example in blood cancers, where it may come with paleness, fever, one infection after another or bruising [2]. But tiredness is very common and usually has another cause [1]. If your tiredness has lasted a few weeks, a doctor usually starts with a full blood count (CBC) [2]. See: symptoms of leukaemia.
Can a blood test show if you have cancer?
There is no blood test that finds every cancer. Tests help, but an abnormal result does not always mean cancer, and a normal result does not always rule it out [10]. A full blood count (CBC) can show signs of blood cancer [2]; but tumour markers such as CA-125 have not been shown to work for finding cancer in healthy people [9]. See: Can a blood test detect cancer? and What is a tumour marker and when is it useful?
I have a small symptom and I am very worried. What should I do?
How are the signs of cancer different in children?
In children, the signs of cancer are a little different: paleness and tiredness that last, unexplained fever, one infection after another, unexplained bruising or bleeding, bone pain, a lump in the belly and a white pupil [2]. Full details: What are the warning signs of cancer in children?
What is cancer and what causes it?
Read the simple explanation of cancer and its causes on these two pages: What is cancer and how does it start? and What causes cancer?
Referral criteria and predictive value of symptoms (for doctors)
For physicians
NICE NG12 (last updated April 2026). Non-site-specific symptoms (section 1.13): unexplained weight loss at age 60 and over (mean loss of more than 5% of body weight within 6 months; recommendation 1.13.2, 2026) and unexplained appetite loss (1.13.3): assess for additional symptoms, signs or findings and offer urgent investigation, a suspected cancer pathway referral or a non-specific symptoms pathway referral; in deep vein thrombosis, "consider" the same (1.13.4). Examples of single-symptom criteria for a suspected cancer pathway referral (diagnosis or exclusion of cancer within 28 days): dysphagia at any age; unexplained haemoptysis at 40 and over; jaundice at 40 and over; an unexplained breast lump at 30 and over; unexplained visible haematuria without UTI at 45 and over; unexplained post-menopausal bleeding (not attributable to HRT) at 55 and over. "Consider" referral: persistent unexplained hoarseness or an unexplained neck lump at 45 and over; oral ulceration lasting more than 3 weeks; unexplained lymphadenopathy or splenomegaly (non-Hodgkin lymphoma, taking into account fever, night sweats, shortness of breath, pruritus and weight loss). Urgent chest X-ray (within 2 weeks) at 40 and over with 2 or more unexplained symptoms, or 1 in anyone who has ever smoked: cough, fatigue, shortness of breath, chest pain, weight loss, appetite loss. Consider a very urgent FBC (within 48 hours) in adults with pallor, persistent fatigue, unexplained fever, unexplained persistent or recurrent infection, generalised lymphadenopathy, unexplained bruising, bleeding or petechiae, or hepatosplenomegaly. Quantitative FIT for an abdominal mass, a change in bowel habit, iron-deficiency anaemia, and at 50 and over with unexplained rectal bleeding, abdominal pain or weight loss, even after a previous negative screening FIT [2]. The NICE threshold for urgent investigation is a positive predictive value (PPV) of 3% [5].
Safety netting. For any symptom associated with an increased risk of cancer that does not meet referral criteria, consider a review, either planned or patient-initiated (new symptoms, continuing concern, or symptoms that recur, persist or worsen); be aware of false-negative chest X-rays and faecal occult blood tests. Tell people being referred that most people referred will not have cancer [3].
PPV of alarm symptoms (GPRD; 762,325 patients aged 15 and over; 3 years after first occurrence). Haematuria for urinary tract cancer 7.4% in men and 3.4% in women; haemoptysis for respiratory tract cancer 7.5% and 4.3%; dysphagia for oesophageal cancer 5.7% and 2.4%; rectal bleeding for colorectal cancer 2.4% and 2.0%. PPV rose with age: haemoptysis in men aged 75–84, 17.1%, and dysphagia in men aged 65–74, 9.0% [4].
Unexpected weight loss (CPRD; 326,240 adults, 2000–2019). 4.8% were diagnosed with cancer within 6 months, 96.3% of them aged 50 and over. The PPV exceeded the 3% threshold in men aged 50 and over and women aged 60 and over; in younger patients, 17 concurrent clinical features in men and 8 in women were associated with cancer. LR+ of tests: low albumin 3.24, raised platelets 3.48, raised WBC 3.01 and raised CRP 3.13; no normal blood test result on its own ruled out cancer [5].
Symptom and stage at diagnosis (English National Cancer Diagnosis Audit 2014; 7,997 patients with 12 solid tumours). The proportion with stage IV disease ranged from 1% for an abnormal mole to 80% for a neck lump. Neck lump, chest pain and back pain were consistently associated with higher odds of stage IV, and abnormal mole, breast lump, post-menopausal bleeding and rectal bleeding with lower odds; for 13 of 20 symptoms, more than 50% of patients were diagnosed at stages other than IV [7]. In a systematic review of 209 studies, evidence linking shorter time to diagnosis with better outcomes was most often reported for breast, colorectal, head and neck and testicular cancer and melanoma [8]. In a community sample (1,724 people aged 50 and over), 53% had had an alarm symptom in the previous 3 months, only 2% cited cancer as a possible cause and 59% had contacted a doctor [6].
Related cancer types
Related questions
References
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