Cancer signs and symptoms
Cancer symptoms are changes in the body caused by the presence of cancer. They are usually caused by the effect of a cancer on the part of the body where it is growing, although the disease can cause more general symptoms such as weight loss or tiredness. There are more than 100 different types of cancer with a wide range of signs and symptoms which can manifest in different ways. Signs and Symptoms. Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body . Cancer can be difficult to diagnose because its signs and symptoms are often nonspecific, meaning they may be general phenomena that do not point directly to a specific disease process. In medicine, a sign is an objective piece of data that can be measured or observed, as in a high body temperature (fever), a rash, or a bruise. A symptom, by contrast, is the subjective experience that may signify a disease, illness or injury, such as pain, dizziness, or fatigue. Signs and symptoms are not mutually exclusive, for example a subjective feeling of fever can be noted as sign by  using a thermometer that registers a high reading. Because many symptoms of cancer are gradual in onset and general in nature, cancer screening (also called cancer surveillance) is a key public health priority. This may include laboratory work, physical examinations, tissue samples, or diagnostic imaging tests that a community of experts recommends be conducted at set intervals for particular populations. Screenings can identify cancers before symptoms develop, or early in the disease course. Certain cancers can be prevented with vaccines against the viruses that cause them (e.g., HPV vaccines as prevention against cervical cancer). Additionally, patient education about worrisome symptoms  that require further evaluation is paramount to reduce morbidity and mortality from cancer. Symptoms that cause excess worry, symptoms that persist or are unexplained, and/or the appearance of several symptoms together particularly warrant evaluation by a health professional. Cancer Signs and Symptoms. Mechanisms Cancer may produce symptoms in one or more of the following ways: Suspicious Symptoms. Symptoms of cancer may be nonspecific changes to the individual's sense of physical well-being (constitutional symptoms), or may localize to a particular organ system or anatomic region. The following symptoms may be manifestations of an underlying cancer. Alternatively, they may point  to non-cancerous disease processes, benign tumors, or even be within the physiological range of normal. They may appear at the primary site of cancer or be symptoms of cancer metastasis, or spread. Further workup by a trained healthcare professional is required to diagnose cancer. Constitutional Symptoms Local Symptoms Cancer Signs: Medical Workup. A health professional may pursue a formal diagnostic workup to evaluate symptoms of cancer. The tests ordered will depend upon the type of cancer suspected. These may include the following: Treatment-Related and Secondary Symptoms. Cancers treatments may include surgery, chemotherapy, radiation therapy, hormonal therapy, targeted therapy  (including immunotherapy such as monoclonal antibody therapy) and synthetic lethality, most commonly as a series of separate treatments (e.g. chemotherapy before surgery). Some of these cancer therapies may produce treatment-related, or secondary, symptoms, including: Symptoms that require immediate treatment include: