• February 18, 2026
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Key Takeaways

  • Without enough sugar (glucose), you may not feel great, and your brain may not work as efficiently, causing you to lose focus and experience brain fog.
  • Blood sugar dips that occur too often may lead to lasting brain damage, affecting thinking.
  • In most cases, low blood sugar can be avoided with a proper diet and medication.

Low blood sugar (hypoglycemia) can happen to anyone and may occur when the level of sugar (glucose) in your blood dips below 70 milligrams per deciliter (mg/dL). Your brain relies on glucose to function normally and is thought to be one of the first organs affected by low blood sugar.

How Blood Sugar Dips Impact Your Focus

You may notice changes in your focus if your blood sugar dips too low.

  • Glucose is your brain’s primary energy source. Your brain has a constant need for glucose since it is a simple sugar that can be used to generate energy quickly. Your brain uses about 20% of the energy your body makes from glucose, which is more than any other organ.
  • Without enough glucose, your brain may start to function improperly. Poor focus is a common symptom of low blood sugar, caused by the brain’s lack of fuel. Low blood sugar may also disrupt how nerve cells (neurons) in your brain communicate.
  • Low blood sugar is associated with slowed reaction time and processing speed. According to one study, hypoglycemia may delay your brain’s response to a stimulus. This may account for the general lack of focus and brain fog you may experience during a blood sugar dip.
  • Certain regions of the brain may be more susceptible to negative effects from low blood sugar. In studies, hypoglycemia has been associated with lower glucose levels in the hippocampus, cerebral cortex, and cerebellum. These brain regions are responsible for learning, memory, processing, spatial awareness, and more.
  • During hypoglycemia, your body may enter a “fight-or-flight” response. This may lead to the release of the hormone adrenaline, which may increase glucose production in your body. This response can cause additional confusion as well as anxiety.
  • If left untreated, chronic hypoglycemia can cause irreversible brain damage. Although more research is needed, some studies indicate that repeated episodes of low blood sugar may cause permanent cognitive impairment, affecting daily tasks, memory, and language.

What Causes Low Blood Sugar

Many things, including diet and specific health conditions, can cause low blood sugar.

Common causes of low blood sugar include:

  • Not eating enough carbohydrates (the primary source of glucose)
  • Intense or excessive physical activity
  • Improper use of diabetes medication, including insulin
  • Consuming alcohol on an empty stomach
  • Diarrhea or vomiting

Specific conditions may also cause low blood sugar:

  • Liver disease
  • Kidney disease
  • Hormonal disorders

Additionally, you may be more likely to get blood sugar dips if you take antibiotics or specific medications for heart disease.

It can be challenging to know if your blood sugar is low. Typical signs of a blood sugar dip include:

  • Increased heart rate
  • Shaking
  • Sweating
  • Anxiety
  • Irritability
  • Confusion
  • Dizziness
  • Hunger

How to Avoid Blood Sugar Dips

There are specific measures you can take to try to avoid blood sugar dips, even if you have diabetes.

  • Eat consistently throughout the day to help manage blood sugar. Avoid skipping meals and eat consistently to ensure your brain has the glucose it needs to function correctly.
  • Protein and fiber-rich foods help keep blood sugar levels steady. Dietary fiber and protein both slow the digestion and absorption of carbohydrates, reducing the risk of low blood sugar caused by insulin overproduction.
  • Consume carbohydrates around intense exercise as needed. Depending on the activity and whether you have diabetes, you may need to consume a carbohydrate snack before, after, or even during exercise to prevent a blood sugar crash.
  • Avoid overconsumption of alcohol. Drinking alcohol (especially heavily or on an empty stomach) may slow the release of glucose by the liver into the bloodstream, leading to potential blood sugar dips.
  • Use a blood sugar monitor if you have diabetes. Blood sugar monitors give you real-time blood sugar readings, which help you know when you may need to adjust your insulin or have a snack to prevent low blood sugar.

For additional help and resources, talk to a healthcare provider to learn how to monitor for low blood sugar and prevent blood sugar dips.

Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Blaabjerg L, Juhl CB. Hypoglycemia-induced changes in the electroencephalogram: an overviewJ Diabetes Sci Technol. 2016;10(6):1259-1267. doi:10.1177/1932296816659744

  2. Mergenthaler P, Lindauer U, Dienel GA, Meisel A. Sugar for the brain: the role of glucose in physiological and pathological brain functionTrends Neurosci. 2013;36(10):587-597. doi:10.1016/j.tins.2013.07.001

  3. Rehni AK, Dave KR. Impact of hypoglycemia on brain metabolism during diabetesMol Neurobiol. 2018;55(12):9075-9088. doi:10.1007/s12035-018-1044-6

  4. Verhulst CEM, Fabricius TW, Nefs G, et al. Consistent effects of hypoglycemia on cognitive function in people with or without diabetesDiabetes Care. 2022;45(9):2103-2110. doi:10.2337/dc21-2502

  5. Jang M, Choi HJ, Lee HJ, Kim HN. Hypoglycemia induces brain metabolic reprogramming and neurodegeneration via serum response factor and myocardin-related transcription factor-ASig Transduct Target Ther. 2025;10(412). doi: 10.1038/s41392-025-02527-x

  6. Genon S, Reid A, Langner R, Amunts K, Eickhoff SB. How to characterize the function of a brain regionTrends Cogn Sci. 2018;22(4):350-364. doi:10.1016/j.tics.2018.01.010

  7. Haas A, Borsook D, Adler G, Freeman R. Stress, hypoglycemia, and the autonomic nervous systemAuton Neurosci. 2022;240:102983. doi:10.1016/j.autneu.2022.102983

  8. Amiel SA. The consequences of hypoglycaemiaDiabetologia. 2021;64(5):963-970. doi:10.1007/s00125-020-05366-3

  9. MedlinePlus. Hypoglycemia.

  10. CDC. Low blood sugar (hypoglycemia).

  11. Ahola AJ, Mutter S, Forsblom C, Harjutsalo V, Groop PH. Meal timing, meal frequency, and breakfast skipping in adult individuals with type 1 diabetes – associations with glycaemic controlSci Rep. 2019;9(1):20063. doi:10.1038/s41598-019-56541-5

  12. Nitzke D, Czermainski J, Rosa C, Coghetto C, Fernandes SA, Carteri RB. Increasing dietary fiber intake for type 2 diabetes mellitus management: A systematic reviewWorld J Diabetes. 2024;15(5):1001-1010. doi:10.4239/wjd.v15.i5.1001

  13. Flores-Hernández MN, Martínez-Coria H, López-Valdés HE, Arteaga-Silva M, Arrieta-Cruz I, Gutiérrez-Juárez R. Efficacy of a high-protein diet to lower glycemic levels in type 2 diabetes mellitus: a systematic reviewInt J Mol Sci. 2024;25(20):10959. doi:10.3390/ijms252010959

  14. Jung AR, Kim H, Kim HS, Kim C, Choi WS. Exercise strategies to prevent hypoglycemia in patients with diabetesKorean J Fam Med. 2021;42(2):91-95. doi:10.4082/kjfm.19.0043

  15. Oba-Yamamoto C, Takeuchi J, Nakamura A, et al. Combination of alcohol and glucose consumption as a risk to induce reactive hypoglycemiaJ Diabetes Investig. 2021;12(4):651-657. doi:10.1111/jdi.13375

  16. Hermanns N, Heinemann L, Freckmann G, Waldenmaier D, Ehrmann D. Impact of CGM on the management of hypoglycemia problems: Overview and secondary analysis of the HypoDE StudyJ Diabetes Sci Technol. 2019;13(4):636-644. doi:10.1177/1932296819831695

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By Brittany Lubeck, MS, RDN

Lubeck is a registered dietitian and freelance nutrition writer with a master’s degree in clinical nutrition.



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