Overview
Breast cancer is a disease in which abnormal cells in the breast grow and can spread to nearby tissue or other parts of the body. It most often begins in the milk ducts or milk-producing lobules. There are several types of breast cancer, and care depends on the type, stage, and features of the cancer.
Key Symptoms
Possible symptoms include a new lump in the breast or underarm, thickening of breast tissue, changes in breast size or shape, skin dimpling, nipple discharge, or a nipple that turns inward. Redness, scaling, or persistent pain can also happen, although pain alone is not a reliable sign. Some breast cancers are found on screening tests before any symptoms are noticed.
Causes and Risk Factors
Breast cancer develops from changes in breast cells that allow them to grow uncontrollably. Risk factors include older age, a personal or family history of breast cancer, inherited gene changes such as BRCA1 or BRCA2, dense breasts, exposure to estrogen over time, alcohol use, excess body weight after menopause, and low physical activity. Having risk factors does not mean a person will definitely develop breast cancer, and some people with breast cancer have no clear risk factors.
Who Is Affected
Breast cancer is one of the most common cancers affecting women worldwide. Men can also get breast cancer, but this is much less common. It can occur in younger adults, though the chance generally increases with age.
Prevention
Not all breast cancers can be prevented, but some risk factors may be lowered. Limiting alcohol, staying physically active, maintaining a healthy weight, and discussing hormone therapy risks with a healthcare professional may help reduce risk for some people. People with strong family histories or inherited risk may benefit from personalized risk assessment and screening plans.
Diagnosis and Tests
Evaluation may begin with a clinical breast exam and imaging tests such as mammography, ultrasound, or MRI, depending on the situation. If an area looks suspicious, a biopsy is usually needed to confirm whether cancer is present. Additional tests may be used to learn the cancer type, whether hormone receptors are present, and whether the cancer has spread.
Treatment Categories
Treatment may include surgery, radiation therapy, chemotherapy, hormone-blocking therapy, targeted therapy, immunotherapy, or a combination of these. The treatment plan depends on the cancer's stage, biology, overall health, and personal preferences. Care is often provided by a team that may include surgeons, cancer doctors, radiation specialists, nurses, and supportive care professionals.
Living With It
Living with breast cancer can affect physical health, emotions, fertility, work, sexuality, and family life. Follow-up care is important to monitor recovery, manage side effects, and watch for recurrence or spread. Support groups, counseling, rehabilitation, and palliative care can be helpful at any stage.
When to Seek Medical Care
Arrange medical evaluation if you notice a new breast lump, persistent breast or nipple changes, unexplained nipple discharge, or swelling under the arm. Also seek care if a screening test shows an abnormal result or if you have a strong family history and want to discuss your risk. Prompt assessment matters even when a symptom does not seem painful or severe.
When It May Be an Emergency
Get urgent medical help for severe shortness of breath, chest pain, coughing up blood, confusion, sudden weakness, or signs of serious infection such as high fever with redness and rapid worsening of breast symptoms. Emergency care is also needed for uncontrolled bleeding, severe dehydration, or sudden severe reactions during cancer treatment. These symptoms may relate to complications of cancer or its treatment.