The signs and symptoms of cancer can vary with the varieties of cancers. However, there are certain common symptoms of cancer that help in identifying the deadly disease at an early stage and increase the chance of curing. The most common signs and symptoms of cancer can roughly be divided into three groups like the local symptoms, the symptoms of metastasis and the systemic symptoms.

There are certain primary symptoms that can detect cancer. These are known as local symptoms. These symptoms include unusual lumps or swelling (tumour), hemorrhage (bleeding), pain and/or ulceration, etc. Compression of surrounding tissues is another local symptom, which may cause other symptoms like jaundice (yellowing the eyes and skin). The symptoms of secondary stage can be called as symptoms of metastasis (spreading). They include enlarged lymph nodes, cough and hemoptysis, hepatomegaly (enlarged liver), bone pain, fracture of affected bones and neurological symptoms. On the other hand, the symptoms of advanced cancer are called as systemic symptoms of cancer. They include weight loss, poor appetite, fatigue and cachexia (wasting), excessive sweating (night sweats), anemia, etc. Specific paraneoplastic phenomena or some specific conditions like thrombosis or hormonal changes are also considered as symptoms of cancer. All these symptoms can be caused due to a variety of conditions.

Another common symptom of cancer is an unexplained weight loss of 10 pounds or more. The cancer-affected people usually lose their weight at some point. The weight loss happens mostly with the patients suffering from cancers of pancreas, stomach, esophagus, or lung. Fever is another symptom of cancer that mainly occurs once the cancer has spread from where it started. This symptom is present in almost all types of cancer, especially when the cancer or its treatment affects the immune system. Fever can make it harder for the body to fight infection. However, fever is considered as an early sign of blood cancers like leukemia or lymphoma. Fatigue is another common symptom of cancer. Fatigue is defined as extreme tiredness that does not get better with rest. This can become an important symptom with the growth of cancer. However, fatigue can happen early in cancers like leukemia, as well.

Pain is also a symptom of cancer; however, it is felt only at an advanced stage. It can be considered as a common symptom, especially in case of the bone cancers or testicular cancer. Usually, a headache that does not go away or respond to treatment is considered as a symptom of a brain tumour. Back pain can be a symptom of cancers in the colon, rectum, or ovary. However, pain is mostly linked to a cancer that has already metastasised (spread from where it started). Certain skin changes can be considered as symptoms of cancer. Apart from the skin cancers, other types of cancers can also have the skin symptoms. The most common skin changes found in cancers include darker looking skin (hyperpigmentation), yellowish skin and eyes (jaundice), reddened skin (erythema), itching, excessive hair growth, etc.

There are also other symptoms of cancers that can be taken into consideration. A change in bowel habits or bladder function is a common syndrome. A change in the size of the stool, long-term constipation, or diarrhea, can be a sign of colon cancer. A relation is found between pain when passing urine, blood in the urine, or a change in bladder function (like needing to pass urine more or less often than usual) and bladder or prostate cancer. Another common symptom of cancer is sores that do not heal. This symptom can be related with skin cancers. A long-lasting sore in the mouth can be a symptom of oral cancer, especially among people who smoke, chew tobacco, or often drink alcohol. Another symptom of cancer is white patches inside the mouth or white spots on the tongue. These patches may be leukoplakia, as well. Leukoplakia is actually a pre-cancerous area, caused by ongoing irritation. Tobacco smoking is one of the main causes behind developing such patches.

Unusual bleeding or discharge is also counted amongst the common symptoms of cancer. It can happen in early or advanced cancer. Bleeding in the sputum (phlegm) can be a sign of lung cancer, and bleeding with stool (or a dark or black stool) can be a sign of colon or rectal cancer. Unusual vaginal bleeding can happen in cancer of the cervix or the endometrium (lining of the uterus). Another common symptom of cancer is thickening or lump in the breast or other parts of the body. A lump or thickening may be an early or late sign of cancer. This is a common symptom in those types of cancers that can be felt through skin. These cancers mostly occur in breast, testicle, lymph nodes (glands), and the soft tissues of the body.

Indigestion or having trouble in swallowing can also be a sign for Cancer. Indigestion or trouble in swallowing is considered as signs of cancer of the esophagus (the swallowing tube that goes to the stomach), stomach, or pharynx (throat). A change in a wart or mole or any new skin change is also considered as symptom of cancer. If any wart, mole, or freckle changes its colour, size, or shape, or loses its definite borders, it can be a symptom of cancer. Continuous cough or hoarseness is another symptom of cancer. Cough may lead to lung cancer, while hoarseness is considered as a sign of cancer of the larynx (voice box) or thyroid.

However, apart from the above mentioned commonly found symptoms of cancer, there are many others that are less common, but important for early identification of cancers.