Short-term side effects occur during the treatment or directly afterward, usually within 6 months.
Common short-term side effects include:
Pain: Some people experience mild discomfort or pain around the breast, or stiffness in the shoulder area. Over time, treatments should become less uncomfortable.
Skin changes: Skin damage is a common side effect of radiation therapy, and having a good skin care routine is essential during treatment. Changes to the skin can include:
peeling or flaking
skin that feels tender, dry, itchy or sore
excess moisture and weeping
Swelling: The breast or surrounding tissue may become swollen or inflamed. Swelling should reduce within a few weeks of the end of treatment.
Hair loss in the armpit or chest: When a doctor applies radiation to the lymph nodes in the armpit and chest, it can cause hair loss in these areas.
A sore throat: Applying radiation to the lymph nodes around the collarbone can cause a sore throat or difficulty swallowing. These symptoms should improve once the treatment is complete.
Fatigue: Radiation can cause someone to feel very tired or fatigued. Being in the hospital and having other treatments, such as chemotherapy, can worsen this fatigue. It is important to sleep and rest as much as possible during treatment.
Nausea: Radiation can cause nausea, but this side effect is extremely rare.
Rib fracture: It is possible for radiation therapy to weaken the ribs, making them more prone to break or fracture. However, with new treatment protocols in practice, this is very rare.
Heart problems: If a doctor applies radiation to the left side of the chest, it can damage the heart. However, with new protocols in place, this is also rare.
Lung problems: Very rarely, radiation causes inflammation in the lungs. The medical term for this is radiation pneumonitis, and symptoms include shortness of breath, a cough, and a low-grade fever, which will go away over time.
A second cancer: In very rare cases, radiation exposure can increase the risk of developing a second cancer.