People living with cancer often experience changes in thinking or memory before, during or after treatment. These may include reduced mental sharpness, trouble finding the right words, a short attention span and forgetfulness—commonly known as “brain fog.” Experts don’t know how to prevent these changes, but there are ways to cope with them.

“Chemo brain” refers to cognitive changes in people undergoing cancer treatment. While chemotherapy is most often blamed for brain fog, it can have many causes, including cancer itself and other types of therapy.

Cancer that arises in or spreads to the brain can lead to impaired cognitive function and mood changes. But people with other types of cancer also experience mental changes. Up to 75 percent of people with cancer may experience cognitive problems during treatment, and about a third will have longer-lasting mental changes, according to the American Society of Clinical Oncology.

Surgery, radiation and some medications—as well as tumors themselves—can trigger inflammation that affects the brain. Some chemotherapy drugs interfere with neuro­transmitters. Hormone therapy that lowers estrogen or testosterone levels can lead to foggy thinking. Some types of immunotherapy can cause neurological side effects. In addition, pain medications are a common cause of confusion and reduced alertness.

What’s more, having a serious illness can bring about stress, anxiety, depression or insomnia, all of which can affect cognition. Cancer and its treatment often cause fatigue, which can affect the ability to concentrate. In many cases, it can be hard to tell whether the underlying illness or its treatment are responsible—and likely both contribute.

Not everyone undergoing cancer treatment will experience chemo brain, and specific symptoms vary from person to person. Risk factors include older age, genetic predisposition and higher medication doses. Changes can range from subtle to impossible to miss. Often these are short-term side effects that will improve after treatment ends, but in some cases, they can be long-term or even permanent.

Brain fog can affect your ability to work or carry out daily activities. Tell your care team if you’re having problems with thinking or memory. There is no standard treatment for cancer-related cognitive problems, but there are ways to compensate.

Identifying the triggers and timing of brain fog is the first step. Many people find it helpful to keep a journal to record their symptoms. For severe problems, a neuropsychologist, occupational therapist or other specialist may be able to help with cognitive rehabilitation.

Coping With Brain Fog

  • Use a daily planner or phone app to keep track of daily activities and to-do lists.
  • Carry paper and a pen to jot down reminders, or use voice memos on your phone.
  • Schedule mentally demanding tasks at times of the day when you feel most alert.
  • Get enough sleep, eat a healthy diet and engage in regular physical activity.
  • Exercise your brain too-try word or math puzzles, playing music or learning a new skill.
  • Tell friends and family what you’re going through and ask for help.