Merck Manual

Please confirm that you are not located inside the Russian Federation

honeypot link

Symptoms of Cancer

By

Robert Peter Gale

, MD, PhD, Imperial College London

Last full review/revision Sep 2020| Content last modified Sep 2020
CLICK HERE FOR THE PROFESSONAL VERSION
GET THE QUICK FACTS
Topic Resources

Sometimes the initial indication is an abnormal result on a laboratory test done for another reason (for example anemia resulting from colon cancer found on a routine complete blood count).

Cancer affects nearby tissues by growing into or pushing on them, thus irritating or compressing them. Irritation typically causes pain. Compression may keep tissues from performing their normal functions. For example, a bladder cancer or a cancerous lymph node in the abdomen may compress the tube (ureter) connecting a kidney with the bladder, blocking the flow of urine. A lung cancer may block airflow through one segment of a lung, causing partial lung collapse and predisposing to infection.

When cancer grows in an area with a lot of space, such as in the wall of the large intestine or the lung cavity, it may not cause any symptoms until it becomes quite large. In contrast, a cancer growing in a more restricted space, such as on a vocal cord, may cause symptoms (such as hoarseness) when it is relatively small. If a cancer spreads (metastasizes) to other parts of the body, the same local effects of irritation and compression eventually occur, but in the new location, so the symptoms may be quite different.

Cancers that involve the membrane covering the lungs (pleura) or the baglike structure that surrounds the heart (pericardium) often ooze fluid, which collects around those organs. Large fluid collections can interfere with breathing or the pumping of the heart.

Table
icon

Pain

Many cancers are typically painless at first, although pain may be an early symptom of some cancers, such as brain tumors that cause headache and head and neck and esophageal cancers that cause painful swallowing. As cancers grow, the first symptom is often a mild discomfort, which may steadily worsen into increasingly severe pain as the cancer enlarges. The pain may result from the cancer compressing or eroding into nerves or other structures. However, not all cancers cause severe pain. Similarly, lack of pain does not guarantee that a cancer is not growing or spreading.

Bleeding

At first, a cancer may bleed slightly because its blood vessels are fragile. Later, as the cancer enlarges and invades surrounding tissues, it may grow into a nearby blood vessel, causing bleeding. The bleeding may be slight and undetectable or detectable only with testing. Such is often the case in early-stage colon cancer. Or, particularly with advanced cancer, the bleeding may be more significant, even massive and life threatening.

The site of the cancer determines the site of the bleeding. Cancer anywhere along the digestive tract can cause bleeding in the stool. Cancer anywhere along the urinary tract can cause bleeding in the urine. Other cancers can bleed into internal areas of the body. Bleeding into the lungs can cause the person to cough up blood.

Blood clots

Weight loss and fatigue

Commonly, a person with cancer experiences weight loss and fatigue, which can worsen as the cancer progresses. Some people notice weight loss despite a good appetite. Others lose their appetite and may even become nauseated by food or have difficulty swallowing. They may become very thin. People with advanced cancer are often very tired. If anemia develops, these people may find that they feel tired or become short of breath with even slight activity.

Swollen lymph nodes

As a cancer begins to spread around the body, it may first spread to nearby lymph nodes Overview of the Lymphatic System The lymphatic system is a vital part of the immune system. It includes organs such as the thymus, bone marrow, spleen, tonsils, appendix, and Peyer patches in the small intestine that produce... read more Overview of the Lymphatic System , which become swollen. The swollen lymph nodes are usually painless, and they may feel hard or rubbery. They may be freely moveable, or if the cancer is more advanced, they may become stuck to the surrounding tissues, or to each other.

Neurologic and muscular symptoms

Cancer can grow into or compress nerves or the spinal cord, causing any of several neurologic and muscular symptoms, including pain, weakness, or a change in sensation (such as tingling sensations). When a cancer grows in the brain, symptoms may be hard to pinpoint but can include confusion, dizziness, headaches, nausea, changes in vision, and seizures. Neurologic symptoms may also be part of a paraneoplastic syndrome Paraneoplastic Syndromes Paraneoplastic (associated with cancer—see also Overview of Cancer) syndromes occur when a cancer causes unusual symptoms due to substances that circulate in the bloodstream. These substances... read more .

Respiratory symptoms

Cancer can compress or block the airways in the lungs, causing shortness of breath, cough, or pneumonia. Shortness of breath can also occur when the cancer causes a large pleural effusion, bleeding into the lungs, or anemia.

NOTE: This is the Consumer Version. DOCTORS: CLICK HERE FOR THE PROFESSONAL VERSION
CLICK HERE FOR THE PROFESSONAL VERSION
Others also read
Test your knowledge
Combination Cancer Therapy
For some cancers, the best approach is a combination of surgery, radiation therapy, and chemotherapy. Sometimes chemotherapy is given before surgery to do which of the following?
 
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID

Also of Interest

Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
Download the Manuals App iOS ANDROID
TOP