From la doctora

Is This Brain Fog, or Something Else?

Someone in your family is forgetting things. It might be you. Here is how to tell what kind of forgetting it is, and what to do next.

Dra. Amanda Perez, MD · Board certified in Family Medicine · 5 min read

Your mom asks the same question twice in ten minutes, and nobody says anything. Somebody changes the subject. Later in the kitchen, your tía says she is just getting old, and that is where it stops.

It should not stop there. Getting old is not a diagnosis. Most families say it and then quit looking. We do this a lot, and it is one reason Latinos get diagnosed late, when the disease is further along.

This is not only about your mom. Half the women who write to me are 43, not 73. They lose a word in the middle of a sentence, or walk into a room and forget why. They read the same page four times and still miss it. Most of them have decided they are lazy or losing their mind. Neither one is true.

What is brain fog?

Brain fog is not a diagnosis. No doctor writes it in your chart. It is a description, like saying your stomach hurts.

That means it has a cause. Usually a boring one. My whole job is finding out which one.

I lose my keys all the time. Is that it?

Probably not. Everyone thinks worse on some days. You sleep four hours and the next day is bad. You sleep well and you feel fine. Fog that comes and goes is telling you about your sleep and your week.

Pay attention when it does not come and go. Watch for these:

It gets worse month after month.
She gets lost on a road she has driven for years.
Other people noticed before she did.

There is one more difference. Misplacing your keys is normal. Finding your keys and not knowing what they are for is not, and that belongs in a doctor's office.

What causes it?

In my exam room, most fog comes down to five things. The list is short, and that is the good news.

SleepYour brain sorts and stores memories while you sleep. Less than seven hours breaks that up. So does waking at night and lying there worried about money.

HormonesEstrogen works on the parts of your brain used for memory and attention. It shifts after a baby, while you breastfeed, and in the years before your periods stop for good. Doctors call that perimenopause. Women in their 40s get told this is stress. Sometimes it is. Often it is timing, and timing can be checked.

Iron and thyroidYou cannot focus on an empty tank. Heavy periods, little red meat, and babies close together pull your iron down. Feeling foggy is one of the first signs. Your thyroid sets the speed of your whole body, including your thinking. Both are simple blood tests, and both get skipped.

Your loadLiving on alert costs you attention and memory. You run a house, a job, and somebody else's appointments. The fog is the price of carrying all of it.

Everything elseSome fog needs a real workup. Low B12, blood sugar, depression, sleep apnea, and early memory disease can all look like this. So can side effects from the pills she already takes.

Four of those five can be sorted out with a blood test and a real conversation. None of them can be sorted out with a tea.

Why do we catch this so late?

Our families absorb things. That is a strength, and it costs us here. Someone notices Mamá repeating herself. One daughter takes over the pills. Somebody stops letting her drive at night. It is done out of love, and it works well enough. Two years pass before anyone says the word doctor.

Getting old is not a diagnosis. Most families say it and then quit looking.

The numbers are hard to argue with. Older Hispanic adults are about one and a half times as likely to have Alzheimer's or another dementia. That is compared to older white adults. The number of us living with it is expected to grow about seven times between 2014 and 2060. That is the steepest rise of any group. We are 18 percent of this country. We are under 1 percent of the people in the Alzheimer's drug trials.

Then there is the visit. You get about eleven minutes. Mamá plays it down because she does not want to be a bother. The visit is in English. Nobody wrote down what has been happening at home. Everyone leaves agreeing it is probably just her age.

Is it nervios or coraje?

People ask me this a lot, and I want to answer it with care.

Nervios, coraje, and susto are real words for real things. Your abuela says she has not been right since the coraje two years ago. She is telling you something useful. She is telling you when it started and what she was carrying. I want to hear that.

The word is still not the cause. Knowing when something started does not explain why it is happening. Families spend years on manzanilla and rest for a thyroid problem that a cheap blood test would have found. Take the word seriously. Do not take it as the answer.

What do I say at the appointment?

Bring paper. It is the cheapest thing you can do and it works.

For one week, write down when the fog is worst. Write down how much she slept. Write down one real example. Could not remember my own phone number at the pharmacy does more in a visit than twenty minutes of talking.

Start with the problem. Say something close to this: I am here for one thing. My memory is changing and it is affecting my day. I want to find the cause.

Ask for the tests by name. Do not say the routine ones. Routine means different things to different doctors, and ferritin often gets left off. Ferritin is the test that shows how much iron you have stored.

If you are told everything is fine and nothing was checked, say this: Please write in my chart that I asked for these tests and you said no.

If this is about your mom, one more thing. Someone goes with her. Not to talk for her, because she will hate that. Go because she will play it down, and someone has to say what the last six months looked like.

I have never had a patient waste my time by bringing notes.

Can I lower the risk?

Yes, more than most people think. A large report in The Lancet in 2024 looked at 14 things we can change. Across a whole population, those 14 are linked to about 45 percent of dementia cases. That is a population number and not a promise to any one person.

Several of those 14 run heavy in our families. High blood pressure, diabetes, hearing loss nobody treated, and being alone too much are all on the list.

Hearing aids matter. Blood sugar matters. Your mom no longer going to misa after your dad died matters too.

The strongest thing I know of for an aging brain does not come in a bottle. It is other people, a reason to get up, and someone who needs you. Our families are good at giving that. Then we take it away the moment someone seems fragile. We stop asking her to cook for the party. We stop putting her on the phone. We do it to protect her, and we remove the thing that was helping.

Ask her to make the rice. Then take her to the appointment.

Educational content from a board certified family physician. Not a diagnosis and not a substitute for your own doctor's evaluation.