The reasons for chemobrain are under study, but several factors may contribute to it:

• Chemotherapy, radiation therapy, and other cancer treatments may set off chemical reactions (such as inflammation) that can affect our cognition, similar to how you may feel when you have the flu. 
• Some chemotherapy medicines may cross the blood-brain barrier. That means some chemotherapy may pass into the brain and affect its functioning.   
• Women taking hormonal therapies, such as tamoxifen and aromatase inhibitors, may also report some chemobrain symptoms.
  
  • Lowering estrogen levels affects brain function, so treatments that suppress estrogen may be a factor.

Besides cancer treatment itself, other factors related to the entire cancer experience may contribute to some chemobrain symptoms. These may include: 

• Poor sleep
• Fatigue related to treatment
• Chronic stress or chronic loneliness
• Under-treatment or over-treatment of pain
• Depression and anxiety
• Lack of exercise or activity
• Poor nutrition
• Side effects of medicines for other conditions, including some nausea and sleep medicines

There are many practical ways you can address chemobrain. Talk with your doctor and healthcare team. It may help to keep a record of the problems you have and when they occur. Bring that information with you to discuss possible solutions with your providers. They might suggest a change in medicine to avoid side effects, or another approach.

These tips may also help you function better:

• Try to get 8 to 9 hours of sleep at night.
• Increase your activity. Aim for moderate exercise, such as walking, yoga, or tai chi, at least three times a week. Even a short walk around the block with a friend or a pet can help. Exercise seems to help many patients with cognitive concerns. 
• Manage your stress. Use music or a calming activity, such as knitting or reading. Consider meditation and other stress-reducing techniques.  Cognitive problems are often magnified when we are under severe stress. 
• If you feel depressed or anxious, talk with your doctor. Treating depression, if you have it, often helps with cognition as well. A referral to an oncology social worker or mental health professional may help.
• Improve your nutrition. Consider decreasing processed and sugary foods in favor of whole foods that have fruits, vegetables, and healthy fats and protein. A nutritionist may help you improve your diet based on your needs. 
• Use lists, calendars, and planners to help you focus and remember important details.
• Organize your living and work spaces. Choose specific places to store items, such as keys or remotes, and always return them to the same spots.
• Socialize. Feelings of chronic loneliness and isolation may put some at greater risk for cognitive problems. Interact with others in ways you enjoy.

Here are some specific tips to help you improve your focus:

• Try to do one thing at a time. We often multitask, but sometimes it helps to focus on the issue at hand.
• Rid yourself of distractions when working on a task.
• Follow a routine. Having a pattern can help you focus.
• Talk to people in quiet places.

If chemobrain feels very intrusive and your doctor doesn’t offer much help, ask to be referred to a speech therapist or a neuropsychologist, a doctor with special training in the connections between the brain and behavior.

In some situations, your doctor may consider using certain medicines, such as methylphenidate (Ritalin) or modafinil (Provigil), to try to improve your concentration.