Can Diabetes Cause Brain Damage?

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Can diabetes cause brain damage?

We all know that diabetes is full of highs and lows and it can have a significant damaging effect on the body.

What about the brain?

How does that roller coaster of blood sugars that is diabetes affect our brain?


I remember one time when visiting my parents, my Dad commented, “look at your mother, see how she’s fading?”

When I took a look at her I easily recognized that her blood sugars were too low but my father mistakenly assumed it was just another symptom of her Alzheimer’s disease.

She could have had a serious medical emergency had I not been there to recognize what was happening and give her some orange juice immediately.

She responded to the orange juice almost instantly and became more alert. That was when I seriously started recommending to my Dad that it was time to put her in a home.

I was no longer comfortable with his ability to be her caregiver and since I lived on the other side of the country I worried about what would happen if I wasn’t there to intervene.

If I wasn’t there, when would he have fed her? Would she have lapsed into unconsciousness and diabetic coma?

Unfortunately, that was a real possibility.

Diabetic coma

That episode with my mother really scared me and got me thinking about how many other people don’t recognize the symptoms when a diabetic is possibly in trouble.

Simply by recognizing what was happening with her I was able to treat the low and avoid a medical emergency.

Can Diabetes Cause Brain Damage - diabetic coma

There are really two ways blood sugars can have a serious effect on a diabetic, hyperglycemia (high blood sugars) and hypoglycemia (low blood sugars).

Both of these, if left untreated can cause serious complications that can result in a diabetic coma or even death.

In either case, doctors are able to quickly and efficiently reverse a diabetic coma, but the treatment depends on what caused the coma.

Hyperglycemic diabetic coma is treated with hydration and insulin.

A hypoglycemic diabetic coma would be treated with glucose and injected glucagon.

The diabetic person usually starts to recover quickly once treatment begins and most will make a full recovery.

However, there may be long-term irreversible brain damage if they do not receive treatment soon after entering a diabetic coma.

Without treatment, the coma could be fatal.

It is important to point out that even without a diabetic coma, the long-term effect of unmanaged blood sugar levels (regardless of high or low) can be damaging.


Hyperglycemia (high blood sugar) occurs when there is too much sugar in the blood.

Can Diabetes Cause Brain Damage - insulin

Type 1 diabetics are unable to produce the insulin that is required in order for the cells to be able to absorb the glucose (sugar) in the blood for energy. So the glucose remains in the blood raising the levels to unsafe levels.

Type 2 diabetics are either don’t make enough insulin or can’t effectively use the insulin they do make causing blood sugar levels to rise dangerously.

In either case, there is too much glucose in the blood and that can cause significant damage to blood vessels throughout the body.

Over time, high blood sugar can damage blood vessels which result in poor blood circulation. Insufficient blood to the brain can cause you to not think as clearly.

An additional problem is that high blood sugar can also increase serotonin and neurotransmitters in the brain. These normally have a positive effect on nerve cells and brain function however too much can actually have the opposite effect.

If blood sugars are left untreated and remain high resulting in serotonin levels remain high it can lead to brain cell damage and inflammation of the brain. Both of these lead to cognitive problems such as memory loss and that feeling of brain fog.


Most diabetics are quite aware of that brain fog that typically accompanies hypoglycemia or low blood sugars.Can Diabetes Cause Brain Damage - fast-acting sugar snacks

Low blood sugars can cause  symptoms like:

  • fatigue
  • headaches
  • brain fog

This is because the brain’s main fuel source is sugar or glucose, when it doesn’t receive enough the brain cells can’t function properly making it difficult to concentrate.

Low blood sugar can occur if you took too much insulin for the amount of food you have eaten, after an intense workout or if you skip meals.

Our 6-year-old grandson is hypoglycemic unaware which simply means he doesn’t feel his lows. It means the rest of us (his caregivers) must watch him more diligently and check him more frequently because he doesn’t feel a low coming on.

We have been trying to teach him to notice how his body feels when he is high or low and he is beginning to notice changes once in a while.

An example would be when I picked him up from school the other day he said he didn’t feel well. I did a finger poke and he was 3.0 mmol/L (54mg/dL). Gave him a fast-acting sugar snack and he was good to go.

It was certainly encouraging that he recognized he felt differently that time he is by no means consistent with recognizing the physical symptoms of his highs and lows.

Diabetic Brain Fog Symptoms

For diabetics, the brain fog they experience from blood sugar swings can be different. Just as different people react to Can Diabetes Cause Brain Damage - brain fogdiabetes differently the same is true for brain fog. Typical symptoms can include:

  • fatigue
  • irritability
  • dizziness
  • confusion
  • memory loss
  • difficulty problem solving
  • trouble finding the right words
  • inability to process information
  • inability to concentrate
  • feeling as if you are moving in slow motion


Strive to keep those blood sugars within the target range as much as possible. Try to avoid those extreme fluctuations.

Always follow the advice of your diabetes care team.Can Diabetes Cause Brain Damage - diabetes supplies

Frequently monitor your blood glucose levels and correct any highs or lows before they become extreme.

Take all medications exactly as prescribed.

Eat a healthy well-balanced diet and choose appropriate snacks.

Regular daily exercise is an important part of diabetes management.

Ensure you get enough sleep each night.

A good diabetes management program will include making healthy choices in all areas of your life.

Not properly managing your diabetes can lead to:

  • cardiovascular disease
  • nerve damage
  • kidney damage
  • amputation
  • increased risk of infection and a cut or sore

Coping with brain fog

As blood sugars improve and return to within target range the brain fog will begin to clear. In the meantime here are a few suggestions to help get you through.

Keep a journal

Can Diabetes Cause Brain Damage? - journal

Both foods and activities can affect your blood sugars. By keeping a journal of what you eat and what activities you engage in will you establish patterns so you can understand how your body responds to various things. Identifying triggers can help you avoid these triggers or know to be prepared for the resulting highs or lows.

Take notes

Brain fog can affect memory so don`t rely on memorization when your mind is unclear. use a notepad on your phone to record anything important you need to remember (appointments, deadlines etc,).

Refrain from making major decisions when your mind is unclear

Hold off on major decisions until your brain fog has cleared. You don`t want to commit to something that you may not have otherwise.

Get enough sleep

The body repairs itself when it sleeps so getting enough sleep is important. Aim for 7 – 8 hours each night. Being tired can make brain fog worse, being well-rested can help keep you sharp and alert.

Go for a walk

Exercise can actually help improve insulin sensitivity allowing your body to use the glucose for energy. If you are feeling a little sluggish go for a short walk. For a type 2 diabetic, this can help improve blood sugar levels and improve alertness.

The Alzheimer’s Connection

In treating diabetes doctors have tended to focus on efforts to prevent physical complications like heart disease and stroke, retinopathy, neuropathy and nephropathy. This has resulted in increased life expectancy which is great news.

Research is increasingly showing strong a link between insulin resistance, memory loss and even Alzheimer`s disease. Both type 1 and type 2 diabetes mellitus are associated with reduced cognitive function.

It seems that more and more people will develop diseases such as Alzheimer`s and diabetes and many believe that if you get one you will likely get the other.

In fact, epidemiologic studies have shown that having type 2 diabetes increases the risk of developing Alzheimer`s by 65% and that 80% of Alzheimer`s patients have problems with glycemic control.

After reading this it now makes much more sense why my mother was diagnosed with both type 2 diabetes and Alzheimer`s disease.

It stands to reason that because my father would misinterpret the symptoms of low blood sugar for reduced cognitive decline and not treat the hypoglycemia there would be resulting permanent brain damage

Safeguarding your brain

Can Diabetes Cause Brain Damage? - doctor

So what can you do to help prevent brain fog if you have diabetes?

Well, preventing the symptoms of brain fog actually begins with maintaining stable blood sugar levels.

If you believe the brain fog is medication-induced, speak with your healthcare provider. They may be able to switch your medication to another type.

Test your blood sugar levels frequently and make any necessary adjustments according to your diabetes care plan.

Eat a healthy, well-balanced diet and avoid excessive sugar.

Drinks plenty of water. Keeping yourself sufficiently hydrated can really help keep those sugars stabilized.

Take medications as prescribed.

Get daily exercise. This doesn`t have to be complicated. A simple 15-minute walk can do wonders although I would work up to at least 30 minutes each day.

Get plenty of sleep, aim for 7-8 hours each night.

Keep all doctor appointments and always follow your doctor’s recommendations.

Final thoughts

Can Diabetes Cause Brain Damage?

The short answer would be a resounding yes, but that doesn`t mean you need to timidly accept this as your fate.

By properly managing your diabetes and avoiding huge fluctuations in blood sugar levels you avoid or at least minimize any resulting brain damage.

You already know that by following your diabetes care plan you avoid physical complications such as:

  • heart disease & stroke
  • retinopathy
  • neuropathy
  • nephropathy

Those same measures can also help prevent brain damage and cognitive decline.

Implement the tips I suggested if you notice you tend to experience brain fog from either low or high blood sugars.

You may notice triggers and by avoiding those triggers or being prepared for them you may be able to maintain more stable control of your blood sugar levels.

Always work closely with your diabetes care team and follow their advice.

I am not in any way a medical practitioner. Please do not rely on the information on our website as an alternative to medical advice from your doctor or another healthcare provider. We only share our experiences. We are affiliates, this means that if you purchase something from a link or ad on this site we may receive a small commission. This in no way affects the price you pay. 

Have you or someone you love experienced diabetic brain fog.

What worked in clearing that up for you.

Leave your suggestions in the comment section below.

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