Forgetfulness is a persistent failure to remember. It results from changes in the brain and can be a normal part of aging or a symptom of another condition or disease. When you experience forgetfulness, you may find it harder to recall information or events, learn new things, or form new memories.

Common causes of forgetfulness include aging, side effects from medications, trauma, vitamin deficiencies, cancer in the brain, and infections in the brain, as well as a variety of other disorders and diseases.
In an aging adult, forgetfulness beyond the normal rate may be a symptom of a disease like Alzheimer’s disease or vascular dementia. It is important to determine the underlying cause of your forgetfulness and begin treatment as soon as possible.

What causes forgetfulness?

Forgetfulness is a normal part of aging, though the exact reason for this is not known and is poorly understood. Forgetfulness along with aging can also be caused by a variety of diseases, such as vascular dementia or Alzheimer’s disease. Head trauma, vitamin deficiency, chronic disease, tumors of the brain, medication side effects, brain infections, stroke, and even anxiety or depression can all cause forgetfulness.

Neurologic causes of forgetfulness

Forgetfulness may be caused by a variety of neurologic conditions including:

  • Alzheimer’s disease
  • Huntington’s disease (inherited disease characterized by dementia)
  • Other forms of dementia
  • Parkinson’s disease (brain disorder leading to tremors and movement disorders)
  • Stroke
  • Vascular dementia

Other causes of forgetfulness

Forgetfulness can also be caused by other conditions including:

  • Anxiety
  • Brain tumors
  • Chronic diseases
  • Depression
  • Head trauma
  • Medication side effects
  • Vitamin deficiency, especially vitamin B12

Serious or life-threatening causes of forgetfulness

In some cases, forgetfulness may be a symptom of a serious or life-threatening condition that should be immediately evaluated in an emergency setting. These include:

  • Encephalitis (inflammation and swelling of the brain due to a viral infection or other causes)
  • Stroke
  • Trauma or head injury

Questions for diagnosing the cause of forgetfulness

To diagnose your condition, your doctor or licensed health care practitioner will ask you several questions related to your forgetfulness. It will be helpful to bring along a family member to help answer questions if you are experiencing forgetfulness. Questions could include:

  • When did you first notice your forgetfulness?
  • Do you have any other symptoms?
  • What medications are you taking?
  • Do you have a family history of dementia?
  • Are you having any trouble with normal daily tasks, such as managing your calendar?

What are the potential complications of forgetfulness?

Forgetfulness is usually not life-threatening by itself, but the underlying cause of forgetfulness can be serious. If your forgetfulness is mild and progressing slowly, it may be a normal part of aging. If your forgetfulness is sudden or progressing rapidly, it is important to determine the cause.

Because forgetfulness can be due to serious diseases, failure to seek treatment can result in serious complications and permanent damage. Once the underlying cause is diagnosed, it is important for you to follow the treatment plan that you and your health care professional design specifically for you to reduce the risk of potential complications including:

  • Difficulty caring for oneself
  • Difficulty communicating
  • Difficulty swallowing or eating
  • Difficulty taking medications
  • Getting lost
  • Impaired judgment
  • Spread of cancer
  • Spread of infection