What Does "CA" Stand for in Medicine?

CA is the abbreviation of the English word "Cancer", which translates to "cancer" or "malignant tumor" in Chinese. Here, it specifically refers to malignant tumors rather than benign ones. In medicine, Cancer, or cancer, primarily refers to malignant tumors originating from epithelial tissue, such as lung cancer originating from bronchial epithelium and esophageal cancer originating from esophageal squamous epithelium. These are currently the most common types of malignant tumors. Epithelial tissue refers to cells and tissues attached to the inner surfaces of hollow organs. For instance, squamous cell carcinoma forms when the squamous epithelium of the bronchus undergoes cancerous transformation, while adenocarcinoma forms when adenoid epithelium undergoes cancerous transformation. In contrast, malignancies originating from mesenchymal tissue are not called cancers but sarcomas, such as osteosarcoma originating from bone tissue and rhabdomyosarcoma originating from striated muscle tissue.

Modern medicine believes that the causes of cancer are diverse. The human body can eliminate cancer cells through immune system suppression. However, when the body's cancer prevention abilities are weakened or suppressed, cancer cells can continue to proliferate and form clinically visible cancers. Both domestic and international medical communities have confirmed that over 80% to 90% of human cancers are related to external environmental factors, meaning that physical, chemical, and biological factors in the human living environment are closely associated with the occurrence of cancer. Adverse environmental exposures are buffered or resisted by the human body's defense system, and their effects can be eliminated or weakened. When carcinogenic factors are too strong or the cumulative effect is too great, and the body has insufficient immune function or lacks repair capabilities, cancer may occur.

1. Lump: Tumors close to the body surface can often be self-detected as lumps, such as breast masses, enlarged thyroid glands or lymph nodes in the neck, or large nodules on the tongue. Women after puberty should learn to perform breast self-examinations.

2. Unexplained fever, fatigue, or progressive weight loss.

3. Persistent indigestion, loss of appetite, easy feeling of bloating after meals, or even vomiting after meals.

4. Abnormal sensations: difficulty swallowing or a sensation of foreign bodies.

5. Changes in bowel habits: alternating constipation and diarrhea, blood or mucus in the stool, painless hematuria, or difficulty urinating.