How to Get Rid of Brain Fog: Causes, Fixes and When to See a Doctor

By Jake Mitchell · Facts checked October 2, 2026

The short answer: brain fog isn’t a disease in itself, and there is no single treatment for it. You clear it by finding what is causing it. The most common causes are poor sleep, stress, poor nutrition, hormonal changes and some medical conditions, and the first fixes doctors suggest are better sleep, regular activity, regular meals and short breaks. If it lasts for weeks or affects daily life, see a doctor.

What brain fog feels like

Cleveland Clinic describes brain fog as a group of symptoms that affect how you think, remember and concentrate. People commonly notice:

• trouble concentrating or paying attention
• forgetfulness and losing your train of thought
• not finding the right words
• slow thinking and reaction time
• mental exhaustion, fatigue or confusion

It is usually temporary. Cleveland Clinic says it can last a few days to weeks, but in some cases months or longer.

Common causes

According to Cleveland Clinic, common causes include:

• Not enough sleep
• Stress, and mental health conditions such as anxiety or depression
• Poor nutrition
• Hormonal changes, for example during pregnancy or menopause
• Diabetes and low blood sugar
• Autoimmune conditions such as lupus, multiple sclerosis and fibromyalgia
• ADHD and autism
• After an illness or treatment: COVID-19 (long COVID), chemotherapy, or a long hospital stay

Brain fog often comes with tiredness. The NHS lists some conditions that cause ongoing tiredness and the signs that point to each:

If you also have…	A doctor may check for
Loud snoring, or gasping or choking noises at night	Sleep apnoea
Low energy, a pounding heartbeat, shortness of breath, pale skin	Iron deficiency anaemia
Feeling very thirsty, peeing more often (especially at night), weight loss	Diabetes
Feeling nervous or irritable, finding it hard to keep still, muscle weakness	Overactive thyroid
Extreme fatigue for at least 3 months, with problems thinking and remembering	ME/CFS (chronic fatigue syndrome)

The NHS is clear: don’t self-diagnose. These signs tell you what to mention to a GP.

What you can do: a checklist

Cleveland Clinic says there is no specific treatment for brain fog, and that a doctor will usually start by suggesting these steps:

1. Fix your sleep first. Adults need 7 or more hours a night (CDC). Go to bed and get up at the same time every day, keep the bedroom quiet and cool, and avoid caffeine in the afternoon and evening.
2. Put screens away before bed. The CDC says at least 30 minutes before bedtime; the NHS says an hour.
3. Avoid big meals, alcohol and exercise right before bed. The NHS suggests not eating, having caffeine or exercising in the couple of hours before sleep.
4. Move every day. Cleveland Clinic suggests 30 minutes of physical activity a day.
5. Eat regular, nutritious meals. Poor nutrition and low blood sugar are both listed causes.
6. Take short breaks during the day so you are not overworking your brain.
7. Write important things down so you don’t have to hold them in your head.
8. Get help for stress, anxiety or low mood. Cleveland Clinic mentions talking therapy such as cognitive behavioural therapy (CBT), and the NHS lists CBT as a possible treatment for ongoing fatigue.
9. Don’t smoke, and keep alcohol low (NHS).

When to see a doctor

See a doctor or GP if:

• the fog is getting in the way of daily life, such as forgetting appointments, struggling with ordinary tasks or not being able to follow conversations (Cleveland Clinic)
• you’ve felt tired for a few weeks and don’t know why (NHS)
• you have other symptoms too, such as weight loss, mood changes, or someone has noticed you gasping or choking in your sleep (NHS)

A doctor may arrange blood tests, for example for anaemia, diabetes or thyroid problems, and treat the cause. If a medicine might be causing the fog, ask before you stop taking it.

A word on “brain fog” supplements

None of the medical sources above recommends a supplement for brain fog in general. If a blood test shows a deficiency, such as low iron, your doctor will tell you what to take. Before buying any product sold for “mental clarity”, read our guides on checking whether a supplement is legit and spotting supplement scams.

Sources

• Cleveland Clinic: Brain Fog (medically reviewed, updated May 2024)
• NHS: Tiredness and fatigue
• CDC: About Sleep