Editing Breast cancer (section)

== Signs and symptoms ==
[[File:Early signs of breast cancer hariadhi svg.svg|350px|thumb|Common symptoms of breast cancer|alt=Cartoons of breasts with a lump, skin dimpling, red fluid leaking from the nipple, or changes in the appearance of the skin or nipple]]
Most people with breast cancer have no symptoms at the time of diagnosis; their tumor is detected by a breast cancer screening test.{{sfn|Hayes|Lippman|2022|loc="Evaluation of Breast Masses"}} For those who do have symptoms, a new [[breast lump|lump]] in the breast is most common. Most breast lumps are not cancer, though lumps that are painless, hard, and with irregular edges are more likely to be cancerous.<ref name=ACS-SS>{{cite web|url=https://www.cancer.org/cancer/types/breast-cancer/screening-tests-and-early-detection/breast-cancer-signs-and-symptoms.html |accessdate=25 March 2024 |title=Breast Cancer Signs and Symptoms |publisher=American Cancer Society |date=14 January 2022}}</ref> Other symptoms include swelling or pain in the breast; dimpling, thickening, redness, or dryness of the breast skin; and pain, or inversion of the nipple.<ref name=ACS-SS/> Some may experience unusual discharge from the breasts, or swelling of the lymph nodes under the arms or along the [[collar bone]].<ref name=ACS-SS/>

Some less common forms of breast cancer cause distinctive symptoms. Up to 5% of people with breast cancer have [[inflammatory breast cancer]], where cancer cells block the [[lymph vessel]]s of one breast, causing the breast to substantially swell and redden over three to six months.<ref>{{cite web|url=https://www.cancer.org/cancer/types/breast-cancer/about/types-of-breast-cancer/inflammatory-breast-cancer.html |accessdate=28 March 2024 |title=Inflammatory Breast Cancer |publisher=American Cancer Society |date=1 March 2023}}</ref> Up to 3% of people with breast cancer have [[Paget's disease of the breast]], with [[eczema]]-like red, scaly irritation on the nipple and [[areola]].<ref name=CRUK-Paget>{{cite web|url=https://www.cancerresearchuk.org/about-cancer/breast-cancer/types/pagets-disease-breast |accessdate=25 March 2024 |title=Paget's disease of the breast |publisher=Cancer Research UK |date=20 June 2023}}</ref>

Advanced tumors can spread (metastasize) beyond the breast, most commonly to the bones, liver, lungs, and brain.{{sfn|Harbeck|Penault-Llorca|Cortes|Gnant|2019|loc="Fig. 9: Common Metastatic Sites in Breast Cancer"}} Bone metastases can cause swelling, progressive [[bone pain]], and weakening of the bones that leads to [[bone fracture|fractures]].<ref name=BCRF-met>{{cite web|url=https://www.bcrf.org/blog/metastatic-breast-cancer-symptoms-treatment/ |accessdate=3 May 2024 |title=Metastatic Breast Cancer: Symptoms, Treatment, Research |date=27 February 2024 |publisher=Breast Cancer Research Foundation}}</ref> Liver metastases can cause abdominal pain, nausea, vomiting, and skin problems – [[rash]], itchy skin, or yellowing of the skin ([[jaundice]]).<ref name=BCRF-met/> Those with lung metastases experience [[chest pain]], shortness of breath, and regular [[cough]]ing.<ref name=BCRF-met/> Metastases in the brain can cause persistent [[headache]], [[seizure]]s, nausea, vomiting, and disruptions to the affected person's speech, vision, memory, and regular behavior.<ref name=BCRF-met/>