Radiation Therapy Side Effects

Across the world, cancer is a formidable challenge, and in Africa, the battle is particularly acute. To put it into perspective, a staggering 70% of countries in sub-Saharan Africa lack even a single radiotherapy machine—a fundamental tool in the fight against cancer. This stark reality underscores the importance of every piece of knowledge we can share, every conversation we can start, about this critical treatment and what it entails.

Radiation therapy is a cornerstone of cancer care. While its purpose is to treat malignancy, it's only natural for patients to wonder about the journey ahead especially the side effects. Knowing what to expect and how to manage these changes is not just about coping; it's about empowerment.

How long do radiation therapy side effects last?

The experience of side effects is deeply personal and generally divided into two main categories: early and late effects. Early side effects begin during or shortly after treatment and are often temporary, while late side effects can develop months or even years later. Keep in mind, the timeline for recovery is unique to each individual.

Early side effects

These are the immediate changes that many people notice as treatment progresses. Common early effects include fatigue, skin changes, and hair loss within the treated area. While uncomfortable, these effects often indicate that your body is actively responding to treatment and typically resolve over time after the course is complete.

Late side effects

Late side effects may appear well after treatment ends and can sometimes be long-lasting or permanent. Examples include long-term changes to the breast such as tissue thickening or gradual fertility or sexual function issues in men due to nerve or vascular impacts. Proactive management and ongoing communication with your care team are essential here.

Returning to work and daily activities

After treatment, many people want to return to their normal routines but it’s vital to listen to your body. Fatigue and other lingering side effects may make full resumption of daily life challenging. A gradual, phased approach starting with part-time or adapted activities can help. Your care team can guide you on when and how best to reintegrate work and daily tasks.

Common side effects of radiation therapy (general)

Fatigue

Fatigue is arguably the most common side effect of radiation therapy. It often begins a few weeks into treatment and can intensify as treatments continue. While it usually fades gradually after therapy ends, it can persist for several months in some cases.

Managing fatigue: Gentle, short walks or light exercise may help boost energy. Planning your day carefully, prioritizing tasks, getting sufficient rest, and maintaining a balanced diet are essential strategies. Don’t hesitate to seek help when needed.

Skin problems

Radiation can cause radiation dermatitis, where the treated skin becomes irritated and sensitive.

Possible symptoms: Redness, swelling, dryness, peeling, blistering, or darkening similar to a severe sunburn.

Care tips: Use loose, soft clothing; avoid harsh soaps or skincare products unless approved by your care team; wash with lukewarm water and gently pat dry; and protect treated skin from sun exposure with clothing or recommended sunscreen.

Hair loss

Hair loss from radiation is often localized to the treatment area and can be deeply emotional.

Hair regrowth: It generally begins after treatment but can be unpredictable sometimes thinner or with a different texture. High-dose treatments may lead to permanent loss.

Coping strategies: Soft hats or scarves, wigs, or style adjustments can help you feel comfortable and maintain confidence.

Side effects of radiation therapy on specific parts of the body

Radiation therapy to the brain

Short-term effects: Headache, nausea, scalp hair loss, or temporary worsening of neurological symptoms are common early responses.

Late effects: Some people may experience cognitive changes such as memory lapses or difficulty concentrating. Your care team can offer cognitive rehabilitation support or management strategies.

Radiation therapy to the head or neck

Mouth care: Avoid hot, spicy, rough, or acidic foods and sugary drinks, alcohol, and tobacco. Sip cool water and use soothing mouthwash or a gentle saltwater rinse.

Dental care: A dental check-up before treatment is important. Continue gentle brushing with a soft brush and fluoride toothpaste, and consult your team before flossing during therapy.

Radiation therapy to the breast

Short-term effects: Redness, swelling, and heaviness in the breast similar to sunburn during treatment.

Long-term changes: Possible alterations in breast shape or firmness due to skin and tissue thickening. Awareness helps manage expectations and preparedness.

How does radiation therapy affect pregnancy?

Radiation is usually avoided during pregnancy due to potential harm to the developing fetus. If you're pregnant, your care team will explore safer alternative treatments.

How does radiation therapy affect fertility?

For women

Radiation to the pelvis or abdomen may harm ovarian function, leading to temporary or permanent infertility or early menopause. If planning for future pregnancy, discuss fertility preservation (e.g., egg or embryo banking) before starting treatment.

For men

Radiation affecting the testicles can reduce sperm count temporarily or permanently. Discuss sperm banking options with your care team before beginning therapy.

How radiation therapy can affect sex

For women

Radiation in pelvic areas may lead to vaginal dryness, discomfort, reduced elasticity, or changes in libido. Lubricants, vaginal dilators, or pelvic floor therapies may help manage these effects.

For men

Radiation near the pelvic region may lead to erectile changes months or years later, often due to nerve or vascular impact. Treatment options including medications can help restore sexual function.

Does radiation therapy cause cancer?

This is a valid concern. Radiation therapy uses high-energy beams to destroy cancer cells, but it can also damage the DNA of healthy cells. Over time, this may slightly increase the risk of a second (new) cancer. While real, this risk is very low, and for nearly all patients, the life-saving benefits of radiation far outweigh this minimal risk.

Published 17th August 2025

References

American Cancer Society: Radiation Therapy Side Effects, Available at: https://www.cancer.org/cancer/managing-cancer/treatment-types/radiation/effects-on-different-parts-of-body.html

Cancer Research UK: Radiotherapy hair loss, Available at: https://www.cancerresearchuk.org/about-cancer/treatment/radiotherapy/side-effects/general/radiotherapy-hair-loss

WebMD: How Radiation Therapy Can Cause Cancer, Available at: https://www.webmd.com/cancer/cancer-caused-by-radiation-therapy#:~:text=need%20to%20know.-,How%20Radiation%20Therapy%20Can%20Cause%20Cancer,treatment%20usually%20outweigh%20this%20risk

Cancer Treatment Centers of America: Does Radiation Cause Cancer?, Available at: https://www.cancercenter.com/community/blog/2024/02/does-radiation-cause-cancer

Share this post:

Read Other Posts