Radiation Therapy and Headaches: Causes, Warning Signs, and Coping Strategies

Radiation therapy to the brain can cause headaches, often due to temporary swelling (brain edema) from treatment effects. Headaches may appear during therapy and sometimes shortly after, and they can come with other neurological symptoms. ^[1] Headaches that do not improve with simple pain relievers (like acetaminophen) warrant prompt evaluation by your care team. ^[2]

Why headaches happen

• Radiation can lead to brain swelling, which may trigger a return of previous neurological symptoms or cause new ones, including headaches, nausea, and changes in vision or balance. ^[1] Headache is one of the common temporary side effects seen with palliative brain radiation as well. ^[3]
• This swelling is usually temporary and often improves after treatment ends, though it may need medication support during therapy. ^[4]

Red flags: when to contact your team urgently

• A headache that does not go away after taking acetaminophen. ^[2]
• New or worsening neurological symptoms: seizures, nausea/vomiting, double vision, unsteady walking, changes in mental status, or speech difficulties. ^[2] If these occur, you should call your doctor or nurse right away so they can evaluate you and provide care. ^[2]

Practical coping strategies

• Use simple pain relief first (e.g., acetaminophen) and monitor response; lack of relief is a signal to contact your care team. ^[2]
• Rest and manage fatigue; feeling unusually tired is common during and right after brain radiation. ^[3]
• Keep a symptom diary noting headache timing, triggers, severity, and associated symptoms; share this with your team for tailored adjustments. ^[5]
• Stay hydrated and eat small, regular meals to reduce nausea that can worsen headache. ^[2]
• Protect sleep and manage stress with gentle relaxation techniques; fatigue and poor sleep can intensify headaches. ^[3]

Medications your team may recommend

• Corticosteroids (such as dexamethasone) are commonly used to reduce brain swelling and relieve headache and nausea related to radiation; dosing is individualized and tapered safely under medical guidance. ^[6] Do not stop dexamethasone without your clinician’s instructions, as it must be reduced gradually. ^[7]
• If nausea accompanies headache, dexamethasone is generally the preferred first agent for brain-related radiation-induced nausea; other antiemetics (like ondansetron or metoclopramide) may be used as needed. ^{[8] [9]}

What to expect over time

• Side effects like headache and fatigue may worsen during treatment but usually start to improve gradually after therapy completes. ^[3] Brain edema-related symptoms often resolve and rarely lead to long-term issues, though monitoring and timely treatment during therapy are important. ^[4]

Safety tips

• Report any new or worsening symptoms promptly; early evaluation helps prevent complications. ^[2]
• Take steroids exactly as prescribed and with food to reduce stomach irritation. ^[6]
• Coordinate all over-the-counter pain relievers with your clinician to avoid interactions and ensure safe dosing during radiation.

Summary

Headaches can occur as a side effect of brain radiation, commonly from temporary swelling; most are manageable with careful monitoring, appropriate medications (often steroids), and supportive strategies. ^[1] Seek urgent care for headaches that do not improve with acetaminophen or if any neurological red flags appear. ^[2]