Brain fog

• Make tasks simpler. Do one demanding thing at a time and put appointments or steps in a calendar or on paper. This works around forgetful moments; it does not treat their cause. [2]
• Look for a pattern. Note your sleep, medicines, other symptoms and what happened before a difficult day. This makes a conversation with your clinician more useful. [1]
• Match activity to your capacity. Take breaks. If activity clearly worsens symptoms, especially after COVID, do not force a gradual increase; ask a clinician for advice. [1]

‘Fog’ can mean losing your train of thought, struggling to find words or feeling mentally slow. It is not a separate disease. Sudden confusion or weakness is an emergency warning, discussed below.

Poor sleep can make you less alert; stress can disrupt concentration and decisions. Illness, mood, alcohol and medicines may also contribute. With noticeable memory problems, thyroid illness or low B12 may sometimes be relevant. These are possibilities, not a home diagnosis: a clinician chooses tests based on your history. Do not stop medicines or take B12 for every kind of brain fog. [2][3]

With long COVID, memory and concentration problems may accompany fatigue or breathlessness; symptoms can vary and worsen after activity. Record what you did and how you felt afterwards. Do not start or increase an exercise programme on your own if activity causes a setback; discuss it first with your clinician or care team. Brain fog alone does not diagnose long COVID, and not all tiredness calls for the same approach. [1]

Keep keys and phone in a fixed place, use a calendar and write down the next step of a task. If possible, choose a quieter time for difficult conversations or work. These tools help you function while the cause is still unknown. Discuss limitations at work or school and predictable setbacks after activity with a clinician; possible long COVID calls for an individual activity plan. [1][2]

Speak to a clinician when symptoms persist, progress or disrupt work, study or daily life. Repeatedly getting lost in familiar places, asking the same questions many times or becoming unable to care for yourself particularly warrants assessment. The clinician can consider sleep, medicines, mood and physical causes. [2]

Sudden severe confusion, difficulty speaking, facial droop, weakness or an abrupt severe headache should not be written off as brain fog. Seek immediate emergency help (112 in the Netherlands, or the local emergency number elsewhere). [4] Even without these warning signs, progressive difficulty is not a reason to self-diagnose a neurological disorder. [2]