Chemo Brain


What is chemo brain?

Chemo brain refers to problems with attention, memory, and thinking during cancer treatment. Other names include chemo fog, chemotherapy-induced cognitive impairment, and cancer treatment-related cognitive impairment.

People often think of cognitive impairment (trouble thinking clearly) as a symptom of chemotherapy. But it can develop before, during, or after any cancer treatment. In some people, it is brief. Others experience it for years.

Common signs of chemo brain include:

  • Confusion or mental fogginess
  • Finding it harder to multitask (do more than one activity at a time)
  • Forgetfulness or short attention span
  • Trouble recalling common words or details such as names and dates
  • Difficulty in making decisions quickly
  • Decreased motor skills

Symptoms and Causes

What causes chemo brain?

Doctors do not always know what causes chemo brain. It can be a side effect of chemotherapy, as some chemotherapy drugs are able to get through the blood-brain barrier. But different issues related to cancer and its treatment may also lead to this symptom.

People may develop chemo brain because of:

  • Cancer treatments other than chemotherapy, such as hormone therapy, and surgery
  • Problems with sleep and nutrition due to cancer treatment, leading to conditions such as anemia and/or sleep apnea
  • Fatigue (extreme tiredness)
  • Stress, depression and anxiety related to a cancer diagnosis
  • The loss of protection provided by the hormones estrogen, progesterone or testosterone when people with breast cancer and prostate cancer are treated with certain hormonal treatments
  • Oxidative stress caused by higher levels of free radicals and damage to DNA
  • Changes to the immune system

Are there risk factors for chemo brain?

There may be risk factors for chemo brain, including:

  • A genetic variation that might make some people more likely to develop chemo brain
  • Age
  • Chemotherapy dosage levels
  • Chemotherapy agent combinations
  • Additional treatments, such as hormone therapy or radiation
  • Other medical conditions such as diabetes and cardiovascular disease

Diagnosis and Tests

How is chemo brain diagnosed?

There are no tests to diagnose chemo brain. Doctors diagnose it based on your description of cognitive problems.

Management and Treatment

How is chemo brain managed or treated?

Doctors do not have a standard treatment for chemo brain. Cognitive rehabilitation programs can be helpful. Some medications have been tested for treating chemo brain but results are varied. These agents include gingko biloba, modafinil, methaphenidate, antidepressants, and donepezil combined with vitamin E.

Many cases of chemo brain are temporary. They go away on their own. However, other cases last for longer periods of time.

What can you do at home to manage chemo brain?

Tracking memory problems in a diary can help you spot potential causes or triggers. This record can also help you schedule important tasks to avoid the most likely issues.

Other steps you can take to cope with chemo brain include:

  • Avoiding multitasking
  • Creating daily routines that are easy to follow
  • Eating healthy foods including vegetables
  • Exercising regularly
  • Getting plenty of rest and sleep
  • Keeping detailed notes and reminders in a daily planner
  • Stimulating your brain with puzzles or learning something new
  • Getting support through counseling and/or groups

Living With

When should I call the doctor about chemo brain?

Tell your doctor if you have thinking, memory, or organization problems that affect your daily life. If these issues continue for a year or more after cancer treatment, be sure to discuss them with your doctor.

Last reviewed by a Cleveland Clinic medical professional on 07/24/2019.


  • American Cancer Society. Chemo Brain. ( Accessed 7/25/2019.
  • Cancer Research UK. About chemo brain. ( Accessed 7/25/2019.
  • National Cancer Institute. Understanding “Chemobrain” and Cognitive Impairment after Cancer Treatment. ( Accessed 7/25/2019.
  • American Cancer Society. Getting Help for Chemo Brain. ( Accessed 7/25/2019.
  • Kovalchuk A, Kolb B. Chemo brain: From discerning mechanisms to lifting the brain fog-An aging connection. ( Cell Cycle. 2017;16(14):1345-1349. Accessed 7/25/2019.
  • Argyriou AA, Assimakopoulos K, Iconomou G, Giannakopoulou F, Kalofonos HP. Either called "chemobrain" or "chemofog," the long-term chemotherapy-induced cognitive decline in cancer survivors is real. ( J Pain Symptom Manage. 2011;41(1):126-39. Accessed 7/25/2019.

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