1. Unintentional Weight Loss Definition: Losing more than 5% of body weight within 6 months without trying. Common Cancers: Pancreatic, stomach, esophageal, and lung cancer. Mechanism: Tumors may increase metabolism or cause systemic inflammation. 2. Persistent Fatigue Definition: Severe tiredness that doesn't improve with rest. Common Cancers: Leukemia, lymphoma, colon cancer. Mechanism: Cancer cells use up nutrients or disrupt normal bodily functions. 3. Prolonged Fever Definition: Fever lasting more than a few weeks without clear infection. Common Cancers: Lymphoma, leukemia, kidney cancer. Mechanism: Tumors may release substances causing fever or indicate infection from a weakened immune system. 4. Changes in Skin Symptoms: New growths, sores that don’t heal, changes in existing moles. Common Cancers: Skin cancer (melanoma, basal cell carcinoma, squamous cell carcinoma). Mechanism: UV radiation damage or genetic mutations affecting skin cells. 5. Lumps and Masses Location: Breast, testicles, lymph nodes, soft tissues. Common Cancers: Breast cancer, testicular cancer, lymphoma, sarcoma. Mechanism: Abnormal cell growth forming palpable masses. 6. Changes in Bowel or Bladder Habits Symptoms: Blood in stool or urine, persistent constipation or diarrhea, changes in urination frequency. Common Cancers: Colon, bladder, prostate cancer. Mechanism: Tumors in the gastrointestinal or urinary tract disrupting normal function. 7. Unexplained Pain Location: Bones, abdomen, back, pelvis. Common Cancers: Bone cancer, ovarian cancer, pancreatic cancer. Mechanism: Tumor pressing on nerves, bones, or organs. 8. Persistent Cough or Hoarseness Symptoms: Chronic cough, hoarseness, coughing up blood. Common Cancers: Lung cancer, laryngeal cancer, thyroid cancer. Mechanism: Tumors in the respiratory tract or vocal cords causing irritation or blockage. 9. Difficulty Swallowing Symptoms: Pain or discomfort when swallowing, feeling of food stuck in the throat. Common Cancers: Esophageal cancer, throat cancer. Mechanism: Tumor obstructing the esophagus or throat. 10. Unusual Bleeding or Discharge Symptoms: Blood in stool or urine, vaginal bleeding outside of normal menstrual cycles, nipple discharge. Common Cancers: Colorectal cancer, bladder cancer, cervical cancer, breast cancer. Mechanism: Tumor affecting blood vessels or adjacent tissues. 11. Chronic Indigestion or Nausea Symptoms: Persistent indigestion, feeling full quickly, nausea. Common Cancers: Stomach cancer, pancreatic cancer, liver cancer. Mechanism: Tumor impacting digestive organs or causing hormonal changes. 12. Persistent Night Sweats Definition: Excessive sweating during the night not related to room temperature or activity. Common Cancers: Lymphoma, leukemia. Mechanism: Tumors affecting the body's temperature regulation or immune response. 13. Changes in Lymph Nodes Symptoms: Swollen, hard, or painless lymph nodes. Common Cancers: Lymphoma, metastatic cancers. Mechanism: Lymphatic spread of cancer cells causing node enlargement. 14. Neurological Symptoms Symptoms: Headaches, vision changes, seizures, balance issues. Common Cancers: Brain tumors, metastatic cancers to the brain. Mechanism: Tumor pressure on the brain or spinal cord. 15. Breast Changes Symptoms: New lumps, skin dimpling, nipple inversion, spontaneous discharge. Common Cancers: Breast cancer. Mechanism: Abnormal cell growth in breast tissue or ducts. 16. Abdominal Swelling and Bloating Symptoms: Persistent bloating, abdominal swelling, discomfort. Common Cancers: Ovarian cancer, liver cancer. Mechanism: Tumors causing fluid buildup or organ enlargement. 17. Testicular Changes Symptoms: Lumps, enlargement, heaviness in the scrotum. Common Cancers: Testicular cancer. Mechanism: Rapid cell division and growth within the testicles. 18. Chronic Sores Symptoms: Sores that do not heal, particularly in the mouth, skin, or genital area. Common Cancers: Skin cancer, oral cancer, genital cancers. Mechanism: Persistent cell damage or immune response to cancerous cells. 19. Unexplained Bruising or Bleeding Symptoms: Frequent bruising, bleeding gums, prolonged bleeding from cuts. Common Cancers: Leukemia, blood cancers. Mechanism: Disruption in blood cell production or clotting factors. 20. Voice Changes Symptoms: Persistent hoarseness or voice changes. Common Cancers: Laryngeal cancer, thyroid cancer. Mechanism: Tumor affecting vocal cords or surrounding structures.