Women undergoing treatment for breast cancer can experience a huge array of side effects. Most women do not experience every possible side effect. Each treatment and combination of treatments can cause different side effects. Which side effects you experience will also depend on your age, any additional health conditions you have, and your overall health. Just like some women have genetic risk factors for breast cancer, your genetic background can raise your risk for some side effects or lower your risk for others.

Some breast cancer treatments carry a higher risk of causing serious side effects than others. For this reason, there are established guidelines for which breast cancer treatments should be tried first and when more aggressive treatments are warranted. Doctors make treatment recommendations based on the type and stage of the breast cancer.

With any breast cancer treatment, the likelihood of serious side effects must be weighed against the risk that the cancer may continue to advance and become life-threatening.

Types of Side Effects From Breast Cancer Treatment

Some side effects are usually temporary, while others may be chronic, or even permanent. To read about the common side effects of a specific medication, surgery, or other type of breast cancer therapy, visit the treatment pages.

Short-Term Side Effects of Breast Cancer Therapy

Many potential side effects of breast cancer treatment are likely to resolve in the weeks or months following the completion of treatment.

• Fatigue
• Hair loss
• Gastrointestinal problems such as nausea, vomiting, diarrhea, and constipation
• Loss of appetite
• Skin irritation similar to sunburn with radiation therapy
• Changes to the skin and nails
• Increased risk for infection
• Mouth and throat sores
• Cognitive problems known as “chemo brain” or “cog fog”
• Muscle pain

Long-Term and Late Side Effects of Breast Cancer Therapy

Late side effects may not occur until months or years after breast cancer treatments have ended. Others may begin during treatment but persist years after treatment is complete. Some side effects of breast cancer treatment can be permanent.

• Changes in the way the breast looks and feels
• Pain or sensitivity in the treated area
• Neuropathy (numbness) due to nerve damage
• Early menopause and infertility in younger women
• Edema (swelling) in the breast
• Lymphedema (swelling caused by the buildup of lymph fluid) in the arm on the treated side
• Osteoporosis (thinning of the bones) that can lead to fractures
• Damage to the heart muscle or lungs
• Challenges with sexuality and intimacy
• Depression
• Fear of breast cancer recurrence
• Hypothyroidism (low thyroid hormone)
• Increased risk for developing another type of cancer
• Weight gain

Condition Guide

• Breast Cancer – An Overview
• Breast Cancer: Stage and Grade
• Breast Cancer Symptoms
• Breast Cancer – The Path to Diagnosis
• Breast Cancer Treatment
• Types of Breast Cancer
• What Causes Breast Cancer?