6 common causes of brain fog and how to address them

             Written by: Monalisa Deka

1 September 2025

Brain fog can make you feel mentally tired, forgetful, or unfocused. It happens for many reasons and doesn’t mean something is seriously wrong. Understanding the causes helps you take small steps toward clearer thinking. 

Photo Credit: Freepik

Sleep helps your brain rest and repair. Poor sleep leads to difficulty concentrating and memory problems. Aim for 7–9 hours of quality sleep per night.

Lack of Sleep

Photo Credit: Freepik

Your brain needs nutrients like vitamins, healthy fats, and protein. Skipping meals or eating too much sugar can cause foggy thinking. Eat balanced meals with whole foods.

Poor Nutrition

Photo Credit: Freepik

High stress increases cortisol, a hormone that affects brain function. This can cause confusion, forgetfulness, or trouble focusing. Practicing relaxation, like deep breathing or light exercise, helps.

Stress & Anxiety

Photo Credit: Freepik

Even mild dehydration affects concentration and alertness. Drink enough water throughout the day. A general guideline is about 8 glasses (2 liters) daily.

Dehydration

Photo Credit: Freepik

Physical activity improves blood flow and brain health. Inactivity can lead to sluggish thinking. Regular exercise, even short walks, can improve mental clarity.

Lack of Physical Activity

Photo Credit: Freepik

Conditions like hypothyroidism, depression, or chronic fatigue can cause brain fog. Certain medications may also impact focus and memory. Consult your doctor if brain fog persists or worsens.

Medical Conditions & Medications

Photo Credit: Freepik