Cancer is a complex group of diseases characterized by uncontrolled cell growth. Our bodies have a system for cell division, growth, and death. In cancer, DNA mutations disrupt this, causing cells to multiply endlessly, ignore death signals, and potentially invade surrounding tissues or spread (metastasize) to distant organs.
Causes vary. A small portion is inherited, but most cases are acquired through lifestyle (smoking, poor diet, obesity, alcohol), environmental exposures (radiation, chemicals), infections (HPV, Hepatitis), and simply aging. Random errors in cell division also contribute.
Types are numerous, named by origin: Carcinomas (skin, organs), Sarcomas (bone, muscle), Leukemias (blood), Lymphomas (lymph system).
Symptoms are diverse and dependent on the cancer's location. Common warning signs include new lumps, unexplained weight loss, persistent fatigue, unusual bleeding, or changes in moles/bowel habits. Early detection is crucial for better outcomes.
Diagnosis often involves physical exams, blood tests (for markers), imaging (CT, MRI, PET scans), and crucially, a biopsy—examining tissue under a microscope to confirm cancer and identify its type.