[someone]

It all started about a month ago when I recovered from flu and the same time my birch pollen allergy kicked in. I got realy weird feeling in my head and at first I could't concentrate. Later I started to forget what was I thinking when something disturbed me for 2s and I started to have problems remembering thing like what I was doing yesterday. It though it was because of the flu and it would go away after few days, but it didn't. I started browsing internet and Brain fog perfectly describes how I fell. It is possible that seasonal allergies such as birch pollen allergy causes brain fog? It is already May and it doesn't seems to get batter. And it also weird because I suffer from allergy 3 years and it didn't happend before.

[Dr. Smith]

Originally Posted by someone

[Is it] possible that seasonal allergies such as birch pollen allergy causes brain fog?

There are many alleged causes of clouding of consciousness (a.k.a. brain fog/mental fog). So many that I'd be looking beyond birch pollen allergy.

Viruses can sometimes have/leave after-effects lasting far longer than the virus itself.

How old are you?

You might also pursue the Searches related to causes of brain fog at the bottom of the first page of links.

Doc

[someone]

I am only 15 years old and that scares my.
I noticed when weather is bad(rainy,cloudy) I can breath more easily and my allergy symptoms decreases so does foggy felling in my head. It is maybe because of lack of oxygen?

[glenntaj]

--you have bronchitis from the flu you experienced, or is it possible you are asthmatic? Either could result in sufficient breathing trouble to give a sensation of light-headedness or fogginess. Of course, even clogged sinuses/sinus infection can make one feel foggy or dizzy.

[Dr. Smith]

Originally Posted by someone

I noticed when weather is bad(rainy,cloudy) I can breath more easily and my allergy symptoms decreases so does foggy felling in my head.

This is fairly common with pollen allergies; rain/humidity can take much of the pollen out of the air. It also reinforces the suspicion of something airborne. Changing weather also involves pressure changes which can affect sinuses (as glenntaj mentioned), but they occur just prior to weather changing.

Allergies can come & go throughout our lifetimes, so you may have more than just birch pollen.

Your age pretty much eliminates any middle-age phenomena , however problems concentrating and forgetfulness go hand in hand with adolescence. Adolescent—or teenage—brain fog has been written about, and is nothing to be too concerned about—you'll outgrow it.

You realize we're not doctors here, and we're just spitballing. Whatever it is, don't let anxiety/fear over this consume you—being 15 is stressful enough, and most of what we stress over are things we all go through in one way or another.

It also couldn't hurt to get checked over by your family doctor.

Doc

[someone]

Well I hope it's just that...
I will wait a week or two and if it wont get batter I will go get myself checked at my doctor...

[someone]

Now 3 months have passed since it started and it didn't get any batter.
My parents dragged me to some alternative medicine thing where I was diagnosed with Birch,Grass,Mite,Weed and Sugar allergy. Is it possible that any of those causes brain fog?

[Dr. Smith]

I would say so, but see what you think.

allergy brain fog

How were these allergies diagnosed, and were they diagnosed as allergies, sensitivities, or intolerances?

allergy vs sensitivity vs intolerance

Doc

[someone]

I have no idea if it is allergy intolerance or sensitivity...
I dont have any problems right after eating any food. But I noticed I have diarrhea more than usual...
I am almost sure that Wheat allergy couses brain fog. What about others?

[Dr. Smith]

Just add them—one at a time—to the allergy brain fog search above and see what turns up.

Doc