Chemotherapy has transformed cancer care, but its benefits come with side effects. “Chemo brain” is the name some people give to the brain fog and fuzziness that can result from these lifesaving treatments.

Chemotherapy works by destroying fast-reproducing cancer cells. But it can kill other healthy cells along the way, including certain brain cells. The destruction of brain cells can impact your emotional state and ability to think, leading to memory and concentration problems, among other concerns.

This article will explore what types of cognitive and emotional changes you might expect from chemotherapy, what factors increase your risk for these symptoms, and what you can do to treat them.

Various emotional and cognitive symptoms can occur during chemotherapy, and they should be categorized separately. Even though they both apply to your brain and can be considered mental side effects, emotion and cognition are different.

Cognition refers broadly to the intellectual processes of absorbing, analyzing, and using information. Emotions are our feelings and responses to experiences, environments, and relationships. For example, trouble focusing is a cognitive side effect, whereas irritability is an emotional one.

Let’s go over some of the most common chemotherapy side effects in both categories.

Cognitive impacts

Cognitive changes are usually the most noticeable — impacting daily functioning, work or school performance, and personal relationships.

Confusion or delirium is the most common of these symptoms, affecting roughly 57 to 85 percent of people undergoing chemotherapy, compared to 15 to 30 percent of people hospitalized for other medical reasons.

Cognitive changes can look different depending on the individual but commonly include:

  • difficulty remembering things
  • short attention span or difficulty concentrating
  • forgetting details
  • unable to multitask
  • difficulty learning new things
  • disorganization
  • slow thinking or processing information
  • trouble finding words or completing sentences

Mental or emotional symptoms

In addition to chemo, other factors can contribute to emotional stress as part of a cancer diagnosis. The emotional impacts of chemo can look like shifts in mood, depression or anxiety. Personality changes are common, too.

These can be linked to chemotherapy treatments, the disease process, and coping with a cancer diagnosis.

Learn more about the emotional impacts of a cancer diagnosis and cancer treatment.

There are several reasons why chemotherapy can impact your mental and emotional health.

One reason is that chemo medications cross the blood-brain barrier, causing inflammation. Brain shrinkage, or a loss of neurons, has been observed as a result of both cancer and chemotherapy.

Cognitive changes can also be heightened by complications of cancer treatment or other medical conditions. Chronic pain and lack of sleep or appetite from chemotherapy treatments can have profound negative life impacts.

This can affect your energy and strength levels, making it hard to focus or regulate your emotions.

Cancer’s spread to the brain can also directly affect cognitive and emotional functioning. This can be separate from, or in addition to, chemo.

While chemotherapy aims to slow or stop the spread of cancer, increased changes in mental status and cognition can also be signs of metastasis, or that the cancer is spreading.

Your doctor may also want to rule out intolerances or reactions to your chemotherapy treatment.

Treating cancer requires an individualized and multidisciplinary approach. Often, a rehabilitation plan is involved in helping you cope with or heal from the effects of chemotherapy and other intensive treatments, including any surgeries.

Your doctor may want to adjust your chemotherapy regimen depending on your side effects.

Cognitive rehabilitation is sometimes included in a chemotherapy plan and offers activities or exercises to help keep your mind sharp and focused during treatment.

The American Cancer Society suggests that exercise and meditation can go a long way in reducing the mental toll of chemotherapy and other cancer treatments.

Also, talk therapy, including cognitive behavioral therapy (CBT), may help you process the complex emotions arising from a cancer diagnosis and treatment.

Talk therapies can help you develop coping techniques that may help you manage fatigue, confusion, and any depression or anxiety you are experiencing due to chemotherapy.

There are particular cancer and chemotherapy medications that can increase the chances of confusion, delirium, and other cognitive changes in some people. Your doctor should review any risks of a potential treatment option with you when designing your chemo regimen.

Consider coming to your appointment prepared with questions about what risk of physical and mental impacts chemo may cause. Ensure your doctor knows all medications you are currently taking to avoid adverse reactions.

If you choose to move forward with treatment, your doctor may be able to help you find ways to preserve your thinking abilities should chemo affect them, or at the very least learn to cope with the changes.

There are certain risk factors that may increase your chance of experiencing mental side effects during chemotherapy.

Besides taking specific medications or having brain cancer, this can include having:

Chemotherapy can effectively manage cancer and bring about remission. But the medications for chemotherapy are strong and highly toxic to other cells and systems in your body. This treatment can cause unpleasant physical, mental, and emotional symptoms.

The physical effects of chemotherapy like nausea and hair loss are well-known, but substantial mental and cognitive changes can also happen with this therapy. “Chemo brain” refers to the fatigue, confusion, and overall brain fog some people experience.

Talk with your doctor about the specific risks versus benefits for your type of cancer, stage, and prescribed chemotherapy regimen. Your medical team should be able to help you with therapies and strategies that can help you cope with the emotional and cognitive toll of cancer and chemotherapy.