Brain Fog and Trouble Concentrating: Possible Causes and What to Check

What it involves

Brain fog is a description people use, not a diagnosis. MedlinePlus describes memory loss as unusual forgetfulness and lists many treatable causes, including sleep problems, stress, depression, certain medicines and low levels of vitamins such as B12. This page uses those sources to explain what a visit looks into.

Who this is for

• Adults who feel mentally foggy, distracted or slow to think
• Patients who forget words, appointments or why they walked into a room more than they used to
• People whose concentration changed after a new medicine, an illness or a stressful period
• Anyone worried that their memory or focus is getting worse

What to expect

• Questions about when the fogginess began, how you sleep, your mood and stress, and everything you take
• A physical exam and a review of your health history, including alcohol use
• Blood tests that can check for problems such as anemia, thyroid trouble, blood sugar and vitamin levels
• A plan for the causes found, or a referral if a memory or neurology evaluation is the next step

Sleep is the first suspect

MedlinePlus says drowsiness, feeling more sleepy than normal during the day, can come from not sleeping long enough, insomnia, shift work, long-term pain and sleep disorders such as sleep apnea. Poor sleep makes it harder to concentrate, so a provider usually starts there. Questions include how many hours you sleep, whether you snore, and whether you wake rested. The sleep apnea and snoring guide explains one common reason that sleep does not refresh, and many people are surprised to learn they stop breathing at night.

Mood, stress and anxiety

MedlinePlus notes that depression, anxiety and stress can contribute to excessive sleepiness, and that memory loss can occur with mental health problems or after a major, stressful event. A provider asks about these directly and without judgment, because treating them often clears the fog. The anxiety symptoms guide and the depression screening guide describe how those questions are asked and what happens next.

Medicines, alcohol and vitamin levels

The MedlinePlus memory loss article lists alcohol and prescription medicine use, overuse of sedating medicines and low levels of vitamins such as B1 or B12 among the causes of memory loss. Antihistamines, sleeping pills and some pain medicines are named as causes of drowsiness. Bring every pill bottle, including over-the-counter sleep aids, to the visit. A provider may check vitamin levels with blood work, and should be the one to change a dose, so please do not stop anything on your own.

Thyroid, blood and other medical causes

MedlinePlus lists an underactive thyroid among the causes of daytime drowsiness, and names diabetes, abnormal blood sodium and high blood calcium as well. Menopause can bring forgetfulness in some women. This is why a visit usually includes blood work, such as the tests described in the thyroid care guide and the memory loss guide. Finding one of these causes is a good outcome, because most of them are treatable.

When forgetfulness is something more

MedlinePlus says normal aging can cause some forgetfulness, such as needing more time to learn new material, but that normal aging does not lead to dramatic memory loss. Memory loss that is sudden, getting worse, interfering with daily tasks or paired with changes in judgment or behavior should be looked at promptly, since it can be a sign of dementia or another brain condition. A provider may refer you for further memory testing or imaging. Bringing a family member who has noticed the changes helps the visit.

When to call 911

Sudden confusion, trouble speaking or understanding, drooping on one side of the face, weakness or numbness on one side of the body, a sudden severe headache, or a fainting spell are emergency symptoms and should not wait for an appointment. MedlinePlus lists a stroke or a transient ischemic attack among the causes of memory loss, and sudden changes after a head injury also need urgent care. For fogginess that has built up over weeks or months, a primary care visit is the right place to begin.

Sources

• MedlinePlus: Memory loss (medical encyclopedia)
• MedlinePlus: Drowsiness (medical encyclopedia)
• MedlinePlus: Menopause (medical encyclopedia)