Understanding Cancer: Causes & Symptoms


Cancer is a term used to describe a group of diseases characterized by the uncontrolled and abnormal growth of cells. In a healthy body , cells grow, divide and die in a controlled manner to maintain the normal functioning of tissues and organs. However , in cancer , this orderly process goes awry , leading to the development of a mass of tissue called a tumor.

Cancer can occur in virtually any type of cell or tissue in the body , and there are more than 100 different types of cancer , each with its own unique characteristic and behavior.

The exact causes of cancer are complex and often involve a combination of genetic, environmental, and lifestyle factors. Mutations or changes in the DNA of cells can disrupt normal cellular processes that regulate growth and division, leading to the development of cancer. Risk factors for cancer can include exposure to carcinogens(cancer causing substances) , tobacco use, unhealthy diet, lack of physical activity , certain infections, and genetic predisposition.


Sign and symptoms caused by cancer will vary depending on what part of the body id affected. Some general sign and symptoms associated with, but not specific to, cancer , include :-

  • Fatigue
  • Lump or area of thickening that can be felt under the skin
  • Weight changes , including unintended less or gain
  • Skin changes , such as yellowing , darkening or redness of the skin , sores that won’t heal , or changes to existing moles.
  • Change in bowel or bladder habits.
  • Persistent cough or trouble breathing.
  • Difficult swallowing
  • Hoarseness
  • Persistent indigestion or discomfort after eating
  • Persistent , unexplained muscle or joint pain.
  • Persistent , unexplained fevers or night sweats.
  • Unexplained bleeding or bruising.


Cancer is a complex and multifaceted group of diseases characterized by the uncontrolled division and growth of abnormal cells in the body. It develops due to genetic mutations and changes that accumulate within cells, disrupting their normal regulatory mechanism. Here’s a general overview of how cancer develops:

  1. Genetic Mutations : Genetic mutations are changes in the DNA sequence of a cell’s genes. These mutations can occur spontaneously or be caused by various external factors, such as exposure to carcinogens (cancer-causing substances) like tobacco smoke, radiation, certain chemicals, and certain viruses.
  2. Initiation : The initial genetic mutations that give rise to cancer are often found in specific genes called oncogenes and tumor suppressor genes. Oncogenes are genes that regulate cell growth and division, and when mutated, they can become overactive, promoting uncontrolled cell growth. Tumor suppressor genes can lead to a loss of their regulatory functions.
  3. Promotion : Following the initiation stage, further genetic mutations can accumulate in the affected cells, leading to the promotion of uncontrolled growth. These mutations can affect various signaling pathways that regulate cell division, DNA repair , and cell death. As these mutations accumulate, the cells become more prone to dividing uncontrollably.
  4. Progression: As the mutated cells continue to divide and accumulate additional mutations, they can develop the ability to invade surrounding tissues and even spread to other parts of the body. This process is know as metastasis. Metastasis is a critical factor in making cancer a serious and potentially life-threatening disease, as it enables the cancer cells to establish secondary tumors in distant organs.
  5. Angiogenesis: In order to sustain their growth, cancer cells often trigger the formation of new blood vessels, a process known as angiogenesis. These blood vessels supply the growing tumor with nutrients and oxygen, allowing it to continue to expand and invade surrounding tissues.
  6. Immune System Evasion: The immune system plays a crucial role in detecting and eliminating abnormal cells, including cancer cells. However, cancer cells can sometimes evade the immune system’s surveillance by developing mechanism to avoid detection or suppress immune responses. This can allow them to continue growing unchecked.


When cancer spreads from its original location to other parts of the body , it is referred to as metastasis. Metastasis is a complex process that involves ;-

  1. Local Invasion : Cancer cells can invade nearby tissues and structures. They can penetrate through the walls of the blood vessels or lymphatic vessels , allowing them to access the circulatory or lymphatic systems.
  2. Intravasation : Cancer cells enter either the bloodstream ( through blood vessels) or the lymphatic system ( through lymphatic vessels). They travel along with the flow of fluids , carried to various parts of the body.
  3. Circulation: Once in the bloodstream or lymphatic system , cancer cell can be transported to distant areas of the body. These cells are now called circulating tumor cells (CTCs).
  4. Arrest and Extravasation : CTCs can become lodged in small blood vessels in different organs or tissues. Here, they need to break through the vessels walls to exit the circulation. This process is called extravasation.
  5. Microscopic Disease : Once cancer cells extravasate , they can begin to multiply and establish tiny, microscopic clusters of cancer cells in the new location. These clusters may not be detectable by imaging or other methods at this stage.
  6. Colonization and Growth : If the conditions in the new location are favorable for the cancer cells, they can continue to grow and divide , eventually forming larger tumors. This is the point where the secondary tumors become clinically detectable .

Metastasis is a significant challenge in cancer treatment because it can make the disease much more difficult to manage. Metastatic cancer is generally considered more advanced and aggressive , and it may require different treatment approaches comparted to localized cancer.


Most cancers have four stages. The specific stage is determined by a few different factors, including the tumor’s size and location:

Stage I: The cancer is localized to a small area and hasn’t spread to lymph nodes or other tissues.
Stage II: The cancer has grown, but it hasn’t spread.
Stage III: The cancer has grown larger and has possibly spread to lymph nodes or other tissues.
Stage IV: The cancer has spread to other organs or areas of your body. This stage is also referred to as metastatic or advanced cancer.

Though stages one through four are the most common, there’s also a Stage 0. This earliest phase describes cancer that’s still localized to the area in which it started. Cancers that are still in Stage 0 are usually easily treatable and are considered pre-cancerous by most healthcare providers.


Cancer is a complex disease that can be caused by a variety of factors, including genetic mutations. Mutations in certain genes can increase the risk of cancer development by disrupting normal cellular processes that control cell growth , division , and death. Here are some types of genes that are commonly associated with causing cancer :

Oncogenes :- Example include the HER2 gene in breast cancer and the BRAF gene in certain types of skin and lung cancers.

Tumor Suppressor Genes :- Example include the TP53 (p53) gene, often referred to as the “guardian of the genome ” and the RB1 gene associated with retinoblastoma.

DNA Repair Genes :- An example is the BRCA1 and BRCA2 genes , which are linked to hereditary breast and ovarian cancers.

Mismatch Repair Genes , Checkpoint Control Genes , Apoptosis – Related Genes : , Apoptosis- Related Genes :, Translocation and Fusion Genes

It’s important to note that cancer development is often the result of multiple genetic and environmental factors interacting. Not everyone with mutation in these genes will necessarily develop cancer , as the context of these mutations in these genes will necessarily develop cancer , as the context of these mutations in these genes will necessarily develop cancer , as the context of these mutations within an individual’s genetic background and environmental exposure also play a crucial role.


There are many different types of cancer , each originating in different tissues or organs . Here are some of the major types of cancer:-

  1. Breast Cancer :- Occurs in the breast tissue, usually in the milk ducts or lobules . It’s the most common cancer among women.
  2. Lung Cancer :- Develops in the lungs and is often linked to smoking , but non-smokers can also develop it.
  3. Prostate Cancer :- Occurs in the prostate gland in men and is one of the most common types of cancer in males.
  4. Colorectal Cancer :- Affects the colon or rectum and is often referred to as colon or rectal cancer , depending on its location.
  5. Skin Cancer :- Includes different types such as basal cell carcinoma , squamous cell carcinoma , and melanoma , which originate from different cell in the skin.
  6. Leukemia :- A type of cancer that starts in blood-forming tissues like bone marrow and affects the production of blood cells.
  7. Lymphoma :- Affects the lymphatic system, which is a part of the immune system. Hodgkin lymphoma and non-Hodgkin lymphoma are the two main types.
  8. Liver Cancer :- Begins in the cells of the liver and can be primary (originating in the liver) or secondary (metastatic, spreading from other organs).
  9. Pancreatic Cancer :- Originates in the pancreas and is often difficult to detect in its early stages.
  10. Ovarian Cancer :- Develops in the ovaries and is often not diagnosed until it has progressed to an advanced stage.
  11. Brain and Central Nervous System(CNS) Tumors :- Can be benign or malignant and can originate in the brain or spinal cord.
  12. Bladder Cancer :- Starts in the bladder lining and is more common in other adults.
  13. Kidney Cancer :- Originates in the kidneys and is often detected at an advanced stage.
  14. Cervical Cancer :- Develops in the cervix, primarily caused by human papillomavirus (HPV)
  15. Esophageal Cancer:- Occurs in the esophagus, the tube that connects the throat to the stomach.
  16. Stomach (Gastric) Cancer :- Affects the stomach lining and can be linked to factors like diet and infection with helicobacter pylori bacteria.
  17. Thyroid Cancer :- Originates in the thyroid gland, which is located in the front of the neck.
  18. Bone Cancer :- Can be primary (originating in the bone) or secondary (spreading from other sites), affecting the bone tissue.
  19. Soft Tissue Sarcoma :- Arises in soft tissues like muscles , tendons, fat, blood vessels , and more.
  20. Multiply Myeloma :- Affects plasma cells in the bone marrow , leading to the overproduction of abnormal antibodies.

These are just a few example , and there are many more types of cancer that can affect various organs and tissues in the body. Each type has its own characteristics, risk factors , and treatment approaches.


  1. Accept practical and emotional support :- Having a network of supportive people is very beneficial for your health , especially emotional support. Studies have compared people with cancer who had the most and least social support . Those with the most social support had better quality of life and lived longer.
  2. Manage stress :- Reducing your stress level can help you maintain your physical and mental health . Here are a few tips to manage stress
  3. Get enough sleep :- Try for 7 to 8 hours of sleep each night. This improves your health , coping ability , mood, weight control , memory and attention and more.
  4. Exercise regularly :- Exercise during and after cancer treatment. This can help reduce fatigue , weight gain , and loss of strength. In addition to regular exercise , try to avoid sitting or lying down for long periods.
  5. Eat well :- A healthy diet can help you manage cancer side effects , recover quicker , and improve health. It may also lower your future risk of cancer.
  6. Immunity Boosters : Vitamin B12 and Vitamin D can be used to boost immunity. Giloy an ayurvedic medicine also used as an immunity booster.

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