Brain Fog

Another blogger recently described being in a very familiar place but feeling he had never been there before. He was unsure of the way home. It must have been an alarming sensation.

I’ve had similar experiences: inability to think or concentrate; forgetting things; feeling lost; mental fatigue. Secretly, you think you might have dementia.

A particular incident stands out. I forgot where I had left my car. It was usually in one of three places. If early to work, I would go for one of two car parks nearby. If later, I would use another a ten-minute walk away. I always remembered which.

One evening I walked back to the wrong car park. I set off for the distant one but just before getting there remembered the car was in one of the others. Annoyed with myself, I turned back. But which of the others was it in? Was it in either? I could not remember. No, it was in the more distant one after all. I turned round again. Or was it? I must have walked there and back twice.

Confused, I returned to work and sat quietly for a time, perhaps half an hour. I phoned home to let them know I was late, without saying why. Eventually, I decided the car must be in the distant car park after all. After quickly glancing round the two nearer ones, I set off again and found it, by that time one of just a few still there. What a relief. 

It was not the only incident. There was the time I missed a regular turning off the motorway and drove for some distance without realising. There were two or three mornings I dropped the children at school and was flashed by other motorists for vacantly crawling along at fifteen miles an hour. I tried to make a cardboard model for my son but could not make sense of the instructions. Out on a work visit, I got lost for much too long in South Manchester and later sat in someone’s office unable to take in much of what they were saying (I made appropriate noises and hopefully got away with it). There were times when my walking felt awkward and disjointed. I fell asleep all the time: like, at half past nine in the morning.

I kept it to myself. You do. Although Mrs. D. did observe bluntly: “There must be something wrong with you when you need to go to sleep at half past nine in the morning.”

In due course I mentioned it to the doctor. I was there about something else but mentioned about feeling extremely tired recently. I didn’t tell him everything: I was too afraid of failing the “What year is it? Who is the Prime Minister? Can you read this address? By the way, what was that address I asked you to read five minutes ago?” examination. He thought it best to do a blood test.

And the result: underactive thyroid. He was surprised. I don’t look like an underactive thyroid. I tend to be underweight. It is four times more common in women than in men. Yet, I had high levels of thyroid stimulating hormone (which means the pituitary is trying to compensate for the underproduction of actual thyroid hormone). It should normally be between 0.4 to 4.0 milliunits per litre. Mine was nearly 10.

I have had to take Levothyroxine every day since. It takes several monthly tests and dosage adjustments to get it right, and then needs to be checked annually, but once it right is you become aware of odd things such as how brittle your nails had become, and that the outer ends of your eyebrows had thinned to nothingness.

That was fifteen years ago. It seems to be sorted now. Either that or I’ve still got it and am too far gone to know.

As the saying goes, every cloud has a silver lining. Hypothyroidism is one of the things that gets you free NHS prescriptions before the age of 60. It’s a bit of a cheek really. It is disturbing to be diagnosed with a “chronic condition” in your fifties until you realise it is hardly any inconvenience at all. Far more serious things don’t get you free prescriptions. Cynic that I am, I suspect that when the list of exemptions was drawn up in the nineteen-fifties, there must have been some government advisor with an underactive thyroid. 


Lots of other things can cause brain fog too, such as stress, lack of sleep, hormonal changes, dietary deficiencies, food allergies, medications and quite a number of medical conditions. For example, see: https://www.healthline.com/health/brain-fog.