Cancer - Symptoms and Types

Cancer is not a single disease but a collection of diseases. Understand better what cancer is and find out the main symptoms.

Cancer is the term used to designate more than 100 different diseases that have in common the uncontrolled growth of abnormal cells that have the capacity to invade tissues and spread to other regions of the body through the vessels.

Dividing cancer cell
Dividing cancer cell

How does cancer appear?

What is cancer?
It is a complicated process, but I'll try to write the simplest way possible. Again the description is not 100% accurate, since this text is not aimed for students in the health field.

The basic life cycle of a cell is to multiply and die if necessary when it becomes old or when it suffers an injury in its structure.

Our cells are programmed for self-destruction in case of change in their original, especially if there is damage to the DNA (genetic code of the cell that determines its characteristics), not subject to repair. This is called self-destruction apoptosis. This mechanism prevents DNA damage that may be perpetuated by the multiplication of abnormal cells.

Cell injuries occur daily in our body and are amplified by cigarette smoking, radiation and chemicals, all substances with high potential for DNA damage (carcinogens). Only the cigarette has over 4000 known carcinogenic substances.

Thanks to apoptosis, we have not developed cancer at all times.

The process of proliferation and apoptosis is controlled by a group of genes called protooncogenes. They are tumor suppressor genes. Cancer begins to arise when mutations occur in these protooncogenes, so that its functions are abolished. The altered genes come to be called oncogenes, and instead of preventing the formation of tumors, they begin to stimulate them.

Thereafter the cells with structural changes cannot multiply, as they are protected from apoptosis. Therefore, cells rapidly proliferate and die. These are cancer cells.

Each type of cancer is related to one or more of various types of protooncogenes. The different types of oncogenes explain why some families have a tendency to develop some types of cancer, and while smoking causes lungs cancer it appears also in some other parts of body mouth, bladder, kidneys, etc. The absence of activation of specific oncogenes also explains why some smokers never develop cancer.

Why cancer leads to death?

In addition to multiplication of cancer cells, they can produce their own blood vessels, which allow them to receive nutrients and form masses of tumor. Another factor is the ability of these abnormal cells to reach the bloodstream and travel throughout the body.

The more damage is done to DNA, the more different it will be from the cell that gave rise to it. And if it is different, it may not crash the vital functions that the original ones exercise. So we now have a framework in which cells do not play any role as they multiply much faster than normal ones and not only compete for food, but they also invade and take the place of normal cells.

After a while there is a situation when a buffer, in which most of the cells are, can not pick up oxygen, a gut does not absorb nutrients, a kidney does not produce urine, etc. In addition, we have a tumor that grows so much that begins to crush and block major blood vessels and other tissues. A tumor of the neck can compress the trachea and cause choking, intestinal tumor obstructs the passage of stool, a brain tumor can compress the brain against the skull etc.

The cancer cell has the ability to invade nearby tissue and reach blood vessels and can travel through the circulation and affect other distant organs. This process is called metastasis. Benign tumors are those who have no ability to metastasize.

Some terms for better understanding:
  • Cancer - abnormal cells are capable of proliferation, invasion and destruction of the distant organs. Cancer is always evil.
  • Tumor is an abnormal increase of the fabric created by malignant cancer cells, but can be benign if there are no cancer cells.
  • Neoplasia - Similar to tumor.
  • Carcinoma is originated cancer of epithelial cells (cell type covering the skin surface and most of the organs).
  • Sarcoma is originated cancer cells of muscle, fat, bone and cartilage.
  • Mesothelioma - Cancer cells originate from the mesothelium, the tissue that surrounds some of our organs such as the pleura, pericardium and peritoneum.
  • Leukemia is cancer that originates from the blood cells in bone marrow.
  • Lymphoma is cancer that originates from cells of the body's defense

Symptoms of cancer

As I have said, there are several types of cancer and each has its distinct clinical presentation. A brain tumor has completely different symptoms of a prostate tumor. However, cancers have a group of signs and symptoms that are more or less common to all.



It is known that all cancer patients suffer from chronic pain. But why does this happen? Most pains are of bone cancers, mainly by metastasis. Any tumor can metastasize to the bone, and patients in terminal stages may present several spontaneous fractures in the body. Headache is also a common symptom and can occur due to metastasis in the skull, brain compression by tumor, hemorrhagic lesions or compression of the facial nerves. The peripheral nerve compression by the tumor mass may be cause of pain at any part of the body. Pain may also be a side effect of chemotherapy and radiotherapy.



Cachexia is a decrease in appetite associated with rapid loss of weight and muscle. Unlike common malnutrition, cachexia is characterized by a weight loss disproportionate lack of caloric intake, which usually cannot be corrected even by force. Tumor cells produce substances that act directly on muscle tissue and adipose (fatty), leading to their consumption. Therefore, cancer patients have such difficulty in gaining weight.


The patient's chronic fatigue can be caused by neoplastic cachexia itself, for anemia due to difficulty in sleeping (usually by pain), and by the direct action of substances produced by tumor. It can be also a side effect of treatment.

Red blood cell
Red blood cell


Anemia is an almost universal finding in cancer. Any chronic disease can cause an inhibition in the production of red blood cells by the bone marrow, and cancer is not an exception. Anemia can also occur due to bleeding of the tumor, by inhibition of iron absorption, by tumor invasion of bone marrow or by direct chemotherapy and radiotherapy.


Patients with malignant tumors tend to have a hypercoagulable state, or inappropriate blood clots inside the vessel, forming clots. There may be thrombosis of arteries and veins, as well as a very serious syndrome called "DIC", where the coagulation cascade begins to be activated in the whole body while there is a simultaneous formation of thrombi and diffuse bleedings.

The occurrence of thrombosis can be the first sign of a tumor, and sometimes precedes the diagnosis of cancer by several months.

For additional information see "14 typical signs and symptoms of cancer".

Specific symptoms of major cancers

In addition to the nonspecific symptoms listed above, common to almost all types of cancers, each also presents a set of specific symptoms related to the affected organ.

Skin cancer
Skin cancer

Symptoms of skin cancer

Skin cancer is the most common type of cancer in hot countries. It occurs mainly in people over 40 and is very rare in children and blacks. There are several different types of skin cancer, basal cell carcinoma, squamous cell carcinoma and melanoma being the most common.

The most common symptoms of skin cancer are skin rash, which can be very similar to signs or new moles, however, that change shape, size and color. Cancer can also be manifested when sores do not heal after four weeks.

Prostate cancer
Prostate cancer

Symptoms of prostate cancer

Prostate cancer is more common in males, however, shows lower mortality than lung cancer and melanoma. It is a cancer that shows slow growth and may take several years to cause symptoms. Currently the majority of prostate cancers are detected before there are clinical symptoms of the disease.

When there are symptoms of prostate cancer, these are difficulty to urinate, reduction of the force of urinary stream, pain during urination, frequent desire to urinate and, more rarely, hematuria. Bone pain can occur in advanced stages, when there are metastases to the bones.
Breast cancer
Breast cancer

Symptoms of breast cancer

Breast cancer is the most common cancer in women. It is rare before 35 years and is more common in patients with positive family history. The most common symptoms of breast cancer are the appearance of nodules or tumors in the breast, changes in skin texture, retraction of the nipple and underarm lymph nodes.

Lung cancer
Lung cancer

Symptoms of lung cancer

Lung cancer is the second most common malignant tumor when one takes into account men and women, and it has the highest mortality. Over 90% of cases occur in smokers. There are four types of lung cancer: small cell carcinoma, squamous cell carcinoma, adenocarcinoma and large cell carcinoma.

The most common symptoms of lung cancer are chronic cough, sputum with blood, chest pain, shortness of breath and recurrent pulmonary infections.

Colon cancer
Colon cancer

Symptoms of colon cancer

The colorectal cancer includes tumors that involve the large intestine and rectum. It is the most common cancers in men and women over 50 years. The main symptoms of colon cancer are anemia by chronic blood loss in stools, which can be perceived or not, abdominal pain, palpable masses in the abdomen, constipation, chronic diarrhea and pain when defecating.

Symptoms of cervix cancer

The cervical cancer is closely related to HPV infection, transmitted through sexual intercourse. The main symptoms of cervical cancer are vaginal bleedings and pelvic pain; however, they only occur in late stages of the disease.
Madnix . Wildsultan

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User discussion

30 May 2012
I am 22 years old and I wonder if daily weakness, body aches and joint pain, headache, difficulty in vision, vomiting, skin looks yellow and red spots in the body are symptoms of cancer! And if so, what tests should I do?
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