Chemo brain


Chemo brain is a side effect of cancer and its treatment. This is characterized by thinking and memory issues that may arise during and after cancer treatment. Chemo brain is often a temporary problem, though some patients continue to have symptoms months after their treatment is over.

Chemo brain is also known as chemo fog, cancer-related cognitive impairment, or cognitive dysfunction.

While the term “chemo brain” is widely used, the precise causes of concentration and memory issues are not fully comprehended, likely stemming from various factors.

Regardless of the underlying cause, chemo brain remains a challenging and debilitating side effect of cancer and its treatment. Ongoing research aims to deepen the understanding of the memory alterations encountered by individuals with cancer.

Although there is no definite treatment for chemotherapy brain fog, drugs, therapies, and activities may be recommended to help clear the fog.


Common symptoms of chemo brain include memory loss and executive function problems. Executive function refers to the capacity for time management and decision-making.

Symptoms may include:

  • Difficulty completing tasks that used to come naturally, such as mentally adding up numbers, or coming up with the appropriate word for a specific object.
  • Experiencing difficulty in keeping up with conversations.
  • Struggling to manage multiple tasks at once.
  • Feeling clumsy, as though there’s an issue with motor abilities.
  • Finding routine tasks taking longer to accomplish than usual.
  • Difficulty in verbal memory, like recalling a conversation.
  • Difficulty in visual memory, such as remembering an image or a list of words.
  • Unusual disorganization
  • Confusion
  • Mental fogginess
  • Short attention span or limited focus
  • Issues with short-term memory
  • Being lethargic, fatigued, or lacking in energy
  • Difficulty picking up new skills

Most cancer survivors are likely to undergo routine checkups. If one notices a sudden worsening of existing chemotherapy-related cognitive problems or develop new symptoms, consult a healthcare provider to determine whether these brand-new or worsening symptoms point to the existence of another medical issue.

It is also generally recommended to maintain a record of the signs and symptoms observed to help the healthcare provider gain a clearer understanding of how these memory issues impact one’s daily activities.


Chemo brain can develop as a result of multiple factors, including the presence of cancer, the medical treatments undergone, specific physical conditions, and other contributing factors.

  • Cancer: Specific cancers can release chemicals that impact memory, and those originating in or spreading to the brain can bring about alterations in cognitive functions. A cancer diagnosis itself can also induce stress, anxiety, and depression, all of which may contribute to thinking and memory issues.
  • Cancer treatments: Cognitive function may be affected by cancer treatments, including bone marrow transplant, chemotherapy, hormone therapy, immunotherapy, radiation therapy, surgery, and targeted drug therapy.
  • Cancer treatment complications: Chemo brain may be caused by complications in cancer treatments, such as anemia, fatigue, infection, hormonal changes, sleep problems, and pain resulting from the cancer treatments themselves.
  • Other causes: Other factors that can contribute to chemotherapy-induced cognitive issues include inherited susceptibility to chemo brain, pain management drugs, and other medical conditions like diabetes, thyroid problems, depression, anxiety, and nutritional deficiencies.

Risk factors

Approximately 75% of individuals undergoing cancer treatment report to their healthcare providers that they experience difficulties with memory, concentration, and their capacity to accomplish tasks.

Several factors that may contribute to a cancer survivor’s risk of experiencing chemo brain include:

  • Getting older
  • Being younger when cancer was diagnosed and treated
  • Had brain cancer
  • Brain metastases, or cancer that spreads to the brain
  • Higher radiation or chemotherapy dosages
  • Brain radiation treatment