What causes head pressure and brain fog?

What is brain fog?

I know exactly what Patient 1 means by 'brain fog'. It is the first symptom I get when I have flu and it is most frustrating as it stops me working. Fortunately, it clears up after a few days. I can't imagine what it must be like to have it for two and a half years.

The first approach would be to make sure this was not a secondary headache - in other words, a headache with an identifiable cause. Some of these are more serious than others and would include giant cell arteritis (an inflammation of the arteries that run along the temples), raised blood pressure (hypertension), brain haemorrhage, brain infections (eg, encephalitis), raised pressure in the fluid of the brain (raised intracranial pressure) and, of course, brain tumours.

Less serious causes (from the point of view of outlook) include carbon monoxide poisoning, taking too many painkillers (medication-overuse headache), disorders of the joints of the jaw (temporomandibular joint disorders), dental problems and sinus infections (sinusitis).

Patient 1 and other forum readers have offered their own theories, based on their own knowledge and experiences. They have raised the possibility of epilepsy, overactive parathyroid glands (hyperparathyroidism), overactive thyroid gland (thyrotoxicosis) and disorders of the brain circulation. Patient 2 suggests it could be a vitamin B12 deficiency.

Fortunately the original poster has had a wide range of investigations including CT and MRI brain scans, a heart tracing, EEG and blood tests, which have ruled out many of these conditions.

Some disorders require specific tests which I can't see Patient 1 has yet had and it would be worth getting these done. These include tests for lupus (an inflammatory disorder), magnesium deficiency, zinc deficiency, Lyme disease (infection resulting from a tick bite) and postural tachycardia syndrome (increase in heart rate on standing). I also think detailed examination and investigation of his neck (cervical spine) would be worth pursuing.

If all these tests are normal, one would be thinking in terms of primary headache (without an underlying secondary cause). Primary headaches are diagnosed in 9 out 10 cases of headache. Common types include tension-type headache, migraine, and daily persistent headache. Diagnosis depends on the pattern of symptoms and investigations to rule out underlying causes. Whilst there are specific therapies for some primary headaches (migraine being a notable example), in many cases, treatment is a trial and error affair.

Sometimes, despite the best efforts of the medical profession and a comprehensive battery of investigations, people are left without any explanation for their symptoms. Doctors (who love to label things) have a name even for this situation - 'medically unexplained symptoms' (MUS). This means exactly what is says on the tin - no one is denying that the person has the symptoms; it's simply that doctors have been unable to find a medical condition to explain them.

Some people with MUS undoubtedly do have stress/anxiety, whether as a result of the symptoms or as a cause of them. I would encourage the poster to continue to pursue psychological support, as this may help to relieve a potential cause as well as helping him cope with the symptoms. Cognitive behavioural therapy would be ideal for this purpose, as would mindful awareness - a technique which would arm him with a way of deflecting his mind away from his troubling symptoms.