4. Headache
At the same time, inflammation can be caused further by low oxygen supply. As the body becomes less efficient at transporting oxygen, this can lead to less oxygen making it into the brain. That in turn can then also cause brain fog and confusion.
Finally, as infection can cause a fever, this can lead to dehydration. Because the brain needs water to operate, this can further make thinking and concentrating difficult. What’s more, is that dehydration causes the brain to actually physically shrink and pull away from the skull – which also leads to headaches and brain fog.
This symptom is most likely to affect older patients: those aged 65 and above.