Cancer: What are the warning signs?

Recognizing the warning signs of cancer: 

In the early stages, the warning signs of cancer are usually vague and general.  Some of the symptoms may even be caused by other illnesses or conditions.  However, even vague symptoms may provide early signs of cancer, with your vigilance resulting in improved early detection, treatment and remission.  Some of these vague symptoms include night sweats, fatigue and new and persistent pain.  A person experiencing any these symptoms should be examined by a physician immediately. Some symptoms are common to various forms of cancer including pain, bleeding, enlarged lymph nodes, unexplained weight loss and nausea.  However, each specific form of cancer also has its own warning signs, such as lumps in the breast in breast cancer, difficulty swallowing in esophageal cancer and yellowish skin (jaundice) in pancreatic cancer. 


A prominent sign of cancer is that when it begins to grow, it eventually starts pressing in on and begins invading surrounding tissues, frequently resulting in pain.  At the very beginning most cancers are not painful, and some even remain painless as they progress.  It is simply not true that all cancers cause pain, and you should never ignore symptoms that are painless believing they are not signs of cancer. 

Cancer tends to lead to bleeding relatively quickly as the cells are not bound together very tightly making them quite fragile.  Cancers may also grow into surrounding blood vessels causing them to bleed.  The location of the bleeding is frequently indicative of where the cancer is developing, with colon cancer resulting in blood in the stool and kidney cancer causing blood to show up in the urine.  However, you need to realize that bleeding can be the result of other diseases besides cancer and is not always definitively a sign of cancer.  Sometimes bleeding is internal and not obvious.  In fact, unusual fatigue that does not improve with rest may be indicative of internal bleeding.  Bleeding and bruising easily may also be indicative of leukemia, although leukemia causes bleeding through a different physiological mechanism. The platelets in the bloodstream are lowered as the bone marrow begins producing cancer cells instead.  People with low platelet levels are known to bleed much easier than people with higher platelet levels. 

Enlarged lymph nodes:  

Some cancers spread quite quickly to nearby lymph nodes in the early stages.  Cancerous lymph nodes become large and hard and may be difficult to move around.  Unlike infected lymph nodes, they are usually painless. 

Weight loss: 

There is frequently some weight loss in the early stages of cancer, although severe weight loss (cachexia) usually does not occur until cancer has progressed. The body releases chemicals called cytokines (there are two types of cytokines: tumor necrosis factor and interleukin 6) in response to the cancer. It is believed, that the cytokines are responsible for the weight loss. Also, weight loss is frequently related to the side effects of cancer treatment, which results in nausea and vomiting for many people. Many people also experience difficulty eating or digesting food because of abnormalities that develop as a result of the cancer such as blockage of the throat, esophagus, or the intestine.  Weight loss may also result from an individual being depressed or experiencing intense fatigue. 


Nausea usually results from chemical changes in the blood which may be the result of increased levels of calcium, decreased levels of sodium, or high levels of urea in the bloodstream.  The spread of the cancer (metastasis) to the brain or liver may also result in nausea. Many people develop nausea as a result of chemotherapy treatment and some of the powerful medications used to treat the resultant pain such as the opiods (OxyContin etc.). 

Other symptoms:

Cancers are usually found as a result of the primary tumor and the resulting symptoms.  Or, sometimes they are found because they spread to other parts of the body resulting in symptoms in those areas.  For example, bone pain may be caused by cancer that has spread to the bone in that specific area.  However, as most people know, much of the pain that older individuals experience are the result of multiple other conditions such as arthritis, and is not indicative of cancer. Altered sensation or weakness may be a sign that a cancer has spread to the brain.  But, similar symptoms may also be experienced by an individual who has had a stroke. 

Cancers frequently release chemicals into the bloodstream that act as hormones.  For example, some cancers release a substance in the blood that is very similar to the effects of parathyroid hormone.  This chemical may then cause the calcium level in the blood to rise resulting in such symptoms as abdominal pain, muscle weakness, mental confusion and diarrhea.  Another chemical released by the cancer may cause effects very similar to the stress hormone cortisol, resulting in a very full, chubby facial appearance and sometimes even stretch marks in the skin.

Some information adapted from The Merck Manual of Health of Aging 

Additional information and web page by Paul Susic Ph.D. Licensed Psychologist Ph.D. 

Psych Talk

Leave a Reply

Your email address will not be published. Required fields are marked *