Understanding Cancer Symptoms
Cancer can cause many different symptoms depending on the type, location, and stage. While some symptoms are obvious, others can be subtle and easy to dismiss. Early detection dramatically improves treatment outcomes for most cancers, which is why knowing the warning signs is critical.
Important: Many symptoms listed here are also caused by benign (non-cancerous) conditions. Having these symptoms doesn't mean you have cancer. However, persistent or unexplained symptoms should always be evaluated by a healthcare provider.
Trust your instincts. You know your body better than anyone. If something doesn't feel right or a symptom persists for more than a few weeks, see your doctor.
⚠️ Seek Immediate Medical Attention If You Experience:
- Severe, sudden headache (especially if different from usual headaches)
- Difficulty breathing or severe shortness of breath
- Severe abdominal pain
- Chest pain
- Coughing up or vomiting blood
- Seizures
- Sudden neurological changes (weakness, numbness, vision changes, confusion)
- Signs of infection with known cancer (fever, severe pain)
General Cancer Warning Signs (CAUTION)
The American Cancer Society's mnemonic for cancer warning signs:
- Change in bowel or bladder habits
- A sore that does not heal
- Unusual bleeding or discharge
- Thickening or lump in breast or elsewhere
- Indigestion or difficulty swallowing
- Obvious change in wart or mole
- Nagging cough or hoarseness
Common Symptoms by Body System
Unexplained Weight Loss
Losing 10+ pounds without trying
- Often first sign of pancreatic, stomach, esophageal, or lung cancer
- Common in lymphoma and leukemia
- May occur with most advanced cancers
- See doctor if you lose 5% or more of body weight over 6 months without diet/exercise changes
Persistent Fatigue
Extreme tiredness that doesn't improve with rest
- Different from normal tiredness - doesn't improve with sleep
- Early sign of leukemia, colon, or stomach cancer
- Can occur with blood loss (colon or stomach cancer)
- Persistent for weeks or worsening = see doctor
Fever
Recurrent or persistent unexplained fever
- Common with blood cancers (leukemia, lymphoma)
- Can occur when cancer spreads
- May be only early sign of blood cancers
- Recurring fevers without clear cause warrant evaluation
Pain
Persistent, unexplained pain
- Headaches that don't respond to treatment (brain tumor)
- Back pain (pancreatic, colon, ovarian cancer)
- Pelvic pain (ovarian, uterine cancer)
- Bone pain (bone cancer, metastases)
- Early sign in some cancers like bone and testicular cancer
Skin Changes
New or changing skin lesions
- New mole or changing mole (melanoma - use ABCDE rule)
- Sore that doesn't heal
- Yellowing of skin/eyes (jaundice - pancreatic, liver cancer)
- Darkening, redness, itching
- Excessive hair growth
Unusual Bleeding or Discharge
Bleeding from any body opening
- Blood in stool (colon or rectal cancer)
- Blood in urine (bladder or kidney cancer)
- Abnormal vaginal bleeding (uterine, cervical, ovarian cancer)
- Bloody nipple discharge (breast cancer)
- Coughing up blood (lung cancer)
Symptoms by Cancer Type
Lung Cancer
- Persistent cough or change in chronic cough
- Coughing up blood or rust-colored phlegm
- Chest pain that worsens with deep breathing, coughing, or laughing
- Hoarseness
- Shortness of breath
- Wheezing
- Recurrent pneumonia or bronchitis
Breast Cancer
- Lump in breast or underarm
- Thickening or swelling of part of breast
- Skin irritation or dimpling (orange peel texture)
- Nipple retraction or discharge (other than breast milk)
- Redness or flaky skin on nipple or breast
- Pain in breast or nipple area
- Any change in size or shape
Colorectal Cancer
- Change in bowel habits (diarrhea, constipation, narrowing of stool)
- Rectal bleeding or blood in stool
- Persistent abdominal discomfort (cramps, gas, pain)
- Feeling that bowel doesn't empty completely
- Weakness and fatigue
- Unexplained weight loss
- Iron deficiency anemia
Prostate Cancer
- Difficulty starting urination
- Weak or interrupted urine flow
- Frequent urination, especially at night
- Blood in urine or semen
- Painful or burning urination
- Difficulty achieving erection
- Pain in hips, back, or pelvis (advanced disease)
Pancreatic Cancer
- Jaundice (yellowing of skin and eyes)
- Dark urine, light-colored stools
- Upper abdominal pain radiating to back
- Loss of appetite
- Unexplained weight loss
- New-onset diabetes
- Blood clots
Ovarian Cancer
- Bloating or increased abdominal size
- Pelvic or abdominal pain
- Difficulty eating or feeling full quickly
- Urinary symptoms (urgency or frequency)
- Fatigue
- Back pain
- Symptoms persistent and represent a change from normal
Brain Tumor
- Headaches that gradually become more frequent or severe
- Morning headaches or headaches that go away after vomiting
- Nausea and vomiting
- Vision problems (blurred, double vision)
- Gradual loss of sensation or movement in arm or leg
- Balance problems
- Speech difficulties
- Seizures
- Personality or behavior changes
Lymphoma
- Painless swelling of lymph nodes (neck, armpit, groin)
- Persistent fatigue
- Fever and chills
- Unexplained weight loss
- Night sweats (drenching)
- Itching
- Shortness of breath or chest pain
Leukemia
- Fatigue and weakness
- Frequent infections
- Fever or chills
- Easy bruising or bleeding
- Tiny red spots on skin (petechiae)
- Swollen lymph nodes
- Enlarged liver or spleen
- Bone or joint pain
- Recurrent nosebleeds
Bladder Cancer
- Blood in urine (most common sign)
- Painful urination
- Frequent urination
- Urgent need to urinate
- Inability to urinate
- Lower back pain on one side
- Pelvic pain
Kidney Cancer
- Blood in urine
- Lower back pain on one side
- Mass or lump in side or back
- Fatigue
- Unexplained weight loss
- Fever not caused by infection
- Anemia
Stomach Cancer
- Poor appetite
- Unexplained weight loss
- Abdominal pain or vague discomfort
- Feeling full after eating small amounts
- Heartburn or indigestion
- Nausea and vomiting
- Vomiting blood or blood in stool
- Swelling or fluid buildup in abdomen
When to See a Doctor
Make an appointment if you experience:
- Any symptom that persists for more than 2-3 weeks without clear cause
- Any symptom that is getting worse rather than better
- Unexplained symptoms that concern you
- Any bleeding from body openings
- New lumps or masses anywhere on your body
- Significant changes in bowel, bladder, or eating habits
- Persistent pain without clear cause
- Unexplained weight loss of 10+ pounds
Remember: Most of these symptoms are NOT cancer. But only a doctor can determine the cause. Early detection dramatically improves outcomes if it is cancer.
Important Reminders
- Don't ignore persistent symptoms. "Waiting to see if it goes away" can delay diagnosis.
- Know your family history. Family history of certain cancers increases your risk and may warrant earlier or more frequent screening.
- Don't self-diagnose. Many cancer symptoms mimic benign conditions. Only a doctor can properly evaluate.
- Be your own advocate. If symptoms persist despite treatment or you're not satisfied with answers, seek a second opinion.
- Participate in recommended screenings. Many cancers can be detected before symptoms appear (mammography, colonoscopy, etc.).
- Trust your instincts. You know your body. If something feels wrong, get it checked out.