Breast pain is extremely common, and in most cases it is not caused by breast cancer.

Hormonal fluctuations, menstrual cycles, pregnancy, breastfeeding, physical activity, injuries, medications, and benign breast conditions can all produce breast tenderness or pain.

That is why breast pain by itself should not automatically be interpreted as a sign of cancer.

However, persistent or unexplained pain that is unusual for you can still be worth discussing with a healthcare professional.

Another symptom to notice is swelling.

If one area of the breast becomes persistently swollen, warmer, redder, or more uncomfortable, several causes are possible. An infection is one possibility, particularly in someone who is breastfeeding.

Inflammatory breast cancer is a rare form of breast cancer that can cause rapid swelling, redness, warmth, skin thickening, and changes in breast appearance. Because these symptoms can resemble infection, persistent or worsening changes should be medically assessed rather than assumed to be one particular condition.

The underarm area also deserves attention.

Lymph nodes are located in the armpit and can become enlarged when the body is responding to an infection. A recent illness, skin irritation, vaccination, or other immune response can temporarily cause swollen lymph nodes.

Nevertheless, a persistent or unexplained lump in the underarm should be evaluated, especially if it does not go away.

A person might notice it while showering or applying deodorant, or a healthcare professional might identify it during an examination.

Other possible changes include a feeling of heaviness, fullness, or unusual discomfort on one side.

These symptoms are not specific enough to diagnose breast cancer, but they can provide a reason to seek professional advice when they persist.

It is also important to understand that breast cancer can sometimes cause no noticeable symptoms at all.

This is one reason age-appropriate breast cancer screening is important. Screening recommendations differ depending on age, personal history, family history, genetic risk, and the guidelines used in a person's country.

Screening and awareness work together: screening looks for abnormalities before they necessarily become noticeable, while awareness helps people recognize changes that appear between routine appointments.

Chapter 5: Knowing What Is Normal—and When to Get Checked

The most important lesson about breast health is not to become frightened by every change.