Why Do I Feel Worse Before I Feel Better?

Dr Vidhi Vaghasiya | MD Radiation Oncologist | Bhavnagar

If you have started radiotherapy and are wondering,

“Why is my swelling still there?”
“Why has my pain increased?”
“I have already taken several radiation sessions. Why don't I feel better yet?”
“Is the treatment even working?”

These are very common questions.

When treatment starts, you naturally expect to feel better. And if you know someone who had surgery for cancer, the difference can be confusing.

They went for an operation, the tumour was removed, and suddenly everyone could say, “The tumour is out.”

With radiotherapy, you may come every day for treatment, feel almost nothing while the machine is running, and still see or feel the tumour afterwards.

So you may wonder: What exactly is happening?

The answer is that surgery and radiotherapy treat tumours in completely different ways.

Surgery Removes the Tumour. Radiotherapy Works Inside It.

Think of surgery as physically removing the tumour.

During an operation, your surgeon removes the tumour and, when necessary, some surrounding tissue or lymph nodes.

Because the tumour has actually been taken out of your body, the physical change can be immediate.

A lump may disappear.
An obstruction may be relieved.
A scan after surgery may no longer show the original mass.

Of course, healing from surgery takes time, and symptoms do not always disappear immediately. But the tumour itself has been physically removed during the operation.

Radiotherapy does not work like that.

Radiation does not cut, burn or pull the tumour out of your body.

Instead, radiation damages the tumour cells so that they lose their ability to keep dividing successfully.

Those damaged cells then gradually die, and your body slowly clears them.

And that takes time.

So please do not expect your tumour to disappear after the first radiation session, after five sessions, or even necessarily on the day you complete treatment.

For some cancers, the response continues for weeks or even months after radiotherapy has finished.

You May Feel the Side Effects Before You Feel the Benefit

This is one of the most important things I want you to understand before or during radiotherapy:

You may notice the treatment before you notice the tumour shrinking.

Radiation is targeting the tumour, but nearby normal tissues inside the treatment area can also temporarily become irritated.

Depending on where you are receiving radiation, you may notice:

This can feel confusing.

You may think:

“If the treatment is working, shouldn't I be feeling better rather than worse?”

Not necessarily.

Your side effects and your cancer response do not always happen at the same speed.

The tumour cells may already be accumulating radiation damage while the surrounding normal tissues are temporarily becoming inflamed.

So feeling uncomfortable during treatment does not automatically mean your cancer is progressing.

“My Pain Has Increased. Does That Mean My Cancer Is Growing?”

Not always.

Pain can temporarily increase during or shortly after radiotherapy.

For example, when radiation is given for painful cancer deposits in bone, some patients can experience a temporary pain flare before the longer-term pain relief develops.

Similarly, temporary inflammation or swelling around the treated area may make certain symptoms feel worse for a short time.

So remember:

Feeling worse during radiotherapy does not automatically mean the tumour is getting worse.

At the same time, please tell your radiation oncology team about worsening symptoms. We need to assess whether they are expected treatment reactions or something requiring additional evaluation.

Radiotherapy Does Not Stop Working on Your Last Day

Many patients reach their final radiation session and think:

“Today my treatment is over. Whatever result I have today must be my final result.”

That is not how radiotherapy works.

The biological effects of radiation continue after your last session.

Tumour cells that have already been damaged may continue to die over the following weeks or months.

That is one reason I may not order your final response scan immediately after treatment.

Depending on your cancer, we may assess your response later through:

The correct timing is different for different cancers.

Every Tumour Has Its Own Speed

Please do not compare your response with another patient's response.

You may meet someone in the waiting area whose lump reduced very quickly.

Your tumour may take longer.

That does not automatically mean their treatment is working better than yours.

Some cancers are highly radiation-sensitive and shrink relatively quickly. Others respond much more gradually.

A fast visible response is not automatically a better final response, and a slower response does not automatically mean radiotherapy has failed.

What matters is whether your tumour is behaving as expected for your cancer type, stage, treatment and individual situation.

What About Benign Tumours?

Radiotherapy is not used only for cancer.

In selected situations, we also use radiation for benign tumours, particularly when surgery may be difficult or risky, or when our main aim is to prevent future growth.

In these cases, I may tell you something that initially sounds surprising:

“I am not necessarily expecting this tumour to disappear.”

Sometimes successful treatment means simply:

It stops growing.

The tumour may remain visible on MRI for years while still being successfully controlled.

Some benign tumours can also temporarily look slightly larger after stereotactic radiation because of treatment-related swelling. We call this pseudoprogression.

So even an early scan that looks somewhat worse does not always mean the treatment has failed.

Your scan needs to be interpreted according to how that particular tumour normally behaves after radiation.

Why Don't We Just Operate on Every Cancer?

You may ask:

“If surgery removes a tumour immediately, why not operate whenever possible?”

Because the fastest way to make a tumour disappear is not always the best treatment.

We choose treatment according to many things:

For some cancers, surgery is best.

For others, radiotherapy or chemoradiotherapy may offer an excellent chance of cure while preserving an organ.

And very often, surgery and radiotherapy are not competitors at all. You may need both as different parts of the same treatment plan.

Please Don't Judge Your Radiotherapy Day by Day

During several weeks of radiotherapy, you will probably have better days and more difficult days.

Your mouth may hurt.
Your skin may become sore.
You may feel tired.
Swallowing may become uncomfortable.
Your pain may fluctuate.

Please do not use each day's symptoms as a test of whether radiation is killing the cancer.

Radiotherapy response is not measured by how you feel after today's session.

We deliver a carefully planned total radiation dose over a specific number of sessions and assess the tumour at the medically appropriate time.

But Please Report Significant Symptoms

Do not assume that every worsening symptom is “just radiation.”

Contact your treating team if you develop severe or rapidly worsening pain, inability to eat or drink, repeated vomiting, significant bleeding, fever, breathing difficulty, rapidly increasing swelling, new weakness or numbness, difficulty walking, confusion, unusual drowsiness, or loss of bladder or bowel control.

These symptoms need proper assessment.

The One Thing I Want You to Remember

If you remember only one message from this article, remember this:

With radiotherapy, you may notice the side effects before you notice the benefit.

Your tumour does not have to disappear immediately for radiotherapy to be working.

Some tumours respond in weeks.
Some take months.
Some benign or slow-growing tumours may take much longer.

And sometimes successful radiotherapy means the tumour stops growing rather than disappears completely.

So if you are midway through treatment and thinking,

“Doctor, I don't feel better yet. Is my radiation working?”

Do not judge the entire treatment by what you feel today.

Keep taking your supportive medicines, report significant symptoms, complete your treatment as advised, and attend your planned follow-up.

Your last radiotherapy session may be the last day you enter the treatment room — but it is not necessarily the last day your radiation is working.