Learn about 12 possible warning signs associated with cancer, including unexplained weight loss, persistent fatigue, unusual bleeding, lumps, and changes in bowel or bladder habits.
12 Possible Warning Signs of Cancer
Cancer can develop without obvious symptoms in its early stages, and different cancers can cause very different symptoms. Still, certain persistent changes deserve medical attention.
1. Unexplained Weight Loss
Losing a significant amount of weight without changing your diet or exercise routine can sometimes be a warning sign. Unintentional weight loss can occur with several cancers, but it can also result from thyroid problems, infections, digestive disorders, stress, and other conditions.
2. Persistent or Unusual Fatigue
Everyone gets tired, but ongoing fatigue that doesn’t improve with adequate sleep and rest deserves attention—particularly when it occurs alongside other unexplained symptoms.
Cancer-related fatigue can result from the disease itself, anemia, inflammation, or other changes in the body.
3. An Unexplained Lump or Swelling
A new lump under the skin, in the breast, neck, armpit, groin, or another area should be evaluated if it persists or changes.
Not every lump is cancerous. Cysts, infections, swollen lymph nodes, and benign growths are common causes.
4. Unusual Bleeding
Unexpected bleeding can sometimes be an important warning sign. Examples include:
- Blood in the stool
- Blood in the urine
- Coughing up blood
- Vomiting blood
- Unusual vaginal bleeding
- Bleeding after menopause
The cause may be something other than cancer, but unexplained bleeding should not simply be ignored.
5. Persistent Changes in Bowel Habits
A prolonged change in bowel habits—including persistent diarrhea, constipation, narrower stools, or a feeling that the bowel doesn’t completely empty—can have many causes.
If the change continues or occurs with blood in the stool, abdominal pain, or unexplained weight loss, seek medical advice.
6. Persistent Changes in Urination
Changes such as blood in the urine, persistent pain during urination, needing to urinate unusually often, or difficulty urinating can have several causes.
Blood in the urine in particular warrants medical evaluation.
7. A Persistent Cough or Hoarseness
A cough that doesn’t go away, recurring coughing up of blood, chest pain, or persistent hoarseness can sometimes be associated with cancer of the respiratory system.
However, infections, allergies, acid reflux, asthma, smoking, and other conditions are much more common explanations.
8. Persistent Difficulty Swallowing
Repeated difficulty swallowing food or liquids, especially when it progressively worsens, should be evaluated.
It can be caused by reflux and other noncancerous conditions, but persistent swallowing problems can also occur with cancers of the throat or esophagus.
9. Persistent Abdominal Pain or Bloating
Occasional bloating or stomach discomfort is common. Persistent or progressively worsening abdominal symptoms, particularly when accompanied by weight loss, changes in bowel habits, or loss of appetite, deserve medical attention.
10. Changes in Skin or a New Mole
Pay attention to a mole or skin lesion that changes in:
- Asymmetry
- Border
- Color
- Diameter
- Evolving appearance
A sore that doesn’t heal, unusual bleeding from a skin lesion, or a rapidly changing spot should also be examined by a healthcare professional.
11. Persistent Fever or Night Sweats
Unexplained recurring fever or heavy night sweating can occur with infections and many other conditions. In some cases, however, they can accompany cancers such as lymphoma or leukemia.
Persistent unexplained symptoms deserve evaluation rather than self-diagnosis.
12. Loss of Appetite or Persistent Indigestion
A sustained loss of appetite, feeling full unusually quickly, or persistent indigestion can have numerous causes. If these symptoms are new, persistent, or accompanied by weight loss, pain, vomiting, or difficulty swallowing, speak with a doctor.
When Should You See a Doctor?
The key word is persistent.
Having one of these symptoms for a short time doesn’t automatically mean cancer. However, make an appointment with a healthcare professional if a symptom:
- Has no obvious explanation
- Doesn’t improve
- Keeps returning
- Gets progressively worse
- Occurs together with other concerning symptoms
- Is accompanied by unexplained weight loss or bleeding
And remember: screening tests can detect certain cancers before symptoms appear. Follow age- and risk-appropriate screening recommendations from your healthcare provider.
Final Thoughts
Your body can sometimes signal that something isn’t right through changes such as unexplained weight loss, persistent fatigue, unusual bleeding, new lumps, or lasting changes in digestion or urination.
But these signs are not a diagnosis of cancer. Many are caused by common and treatable conditions.
The safest approach is simple: don’t panic, but don’t ignore persistent unexplained changes either. Early medical evaluation can identify the actual cause and, when cancer is present, may help with earlier diagnosis and treatment.
Medical disclaimer: This article is for general educational purposes and is not a substitute for medical diagnosis or professional medical advice.