High or low blood glucose making you cranky? Here’s why

Woman checking blood sugar level

Gina McKelvey

Mood changes can be a common experience in people with diabetes, both type 1 and type 2. Medtronic Diabetes Clinical Manager Gina, who has lived with type 1 diabetes for more than 39 years, addresses the affect blood sugar levels can have on your everyday emotions. 

The other day, I was driving and was suddenly overcome by a feeling of intense sadness; I started to cry. At the time, I thought I was reacting emotionally to a stressful week; I had been looking for a home to purchase, and my offer on a townhome I really liked had been rejected. Then, my Low Predictive alert sounded on my pump, and I realized the reason for the sudden change in my emotions was because my blood glucose (BG) had been dropping and was approaching a low level. Once my BG stabilized, I was fine. The sadness went away as quickly as it had come. Has this ever happened to you?


There is a Reason: Your Brain!

Well, there is an explanation! Your brain, the center of your thoughts and emotions, needs glucose to do its job. If you don’t have enough glucose to “feed your brain,” your brain can go “haywire”. Even though it seems like you are overly emotional, this is really a physical response to low BG (hypoglycemia). You don’t have to be below a certain number, like 70 mg/dL, to experience this. Your BG may be in the 80-130 md/dL range, or possibly higher, when the reaction occurs. It can be due to a rapid drop in your BG level instead of the actual level (1). 

Can high BG’s (hyperglycemia) affect your immediate emotions? It probably will not surprise you the answer is “yes.” High BG’s can make it difficult to think and concentrate. I know some people with diabetes tend to get grouchy and irritable when our sugar is high because any blood sugar outside of our desired range can make us feel weird, uncomfortable, and emotionally off-balance (2). This can all vary greatly from person to person, but it’s an interesting symptom to be aware of.


Our Friends and Family

Those who know me well know that if I say I am feeling “wonky” or “out of sorts,” or if I am acting out of character, it could be a BG issue. I have to admit when these same people, people I care for deeply, suggest I check my BG, I have been known to react in a less than positive way that requires an apology later. Thankfully, these same friends and family members know the rudeness is not “me,” but my brain’s reaction to lack of sugar/energy.


Sense of Humor: Critical when Living with Diabetes!

Remember that Snickers® campaign ad from a couple of years ago that showed someone having less than desirable behavior? A friend would tell the person to eat a Snickers candy bar, and suddenly the behavior was gone and the true person reappeared. The negative change in personality was due to lack of brain fuel. They needed sugar! This may be a good way to explain it to your friends and family (when your BG is normal) so they have something other than your behavior to base their responses on. That way, they are less likely to be offended if you lash out at them. It may actually add some humor to an often difficult situation. 

You may tell your friends and family, “If I start acting like Oscar the Grouch (insert your choice of character) for no reason, it might be because my BG level is dropping, or because my sugar is too high. Try not to take it personally and just guide me through the process of testing my BG and treating the low/high as indicated. I apologize in advance if I act mean and nasty, and I truly appreciate your love and support.” 

By the way, I am not suggesting you use a candy bar to treat a low BG, as it may have too much fat to treat a low; always follow the advice of your healthcare team (not a TV commercial) when treating low BG’s! 


Online References:
  1. http://www.diabetesforecast.org/2013/nov/can-diabetes-affect-my-mood.html
  2. http://consumer.healthday.com/mental-health-information-25/anxiety-news-33/diabetes-can-take-a-toll-on-your-emotions-664847.html


Gina Family


Guest Blogger – Gina Addy McKelvey, FNP, CDE

Gina Addy McKelvey is a Family Nurse Practitioner, Certified Diabetes Educator, and Medtronic Diabetes Clinical Manager in Charleston, South Carolina. She has been living with type 1 diabetes for 39 years, and believes those living with diabetes can live long, healthy, productive, happy lives. She’s thrilled about the advances in diabetes management she’s witnessed over 39 years, and believes the best is yet to come. Gina has used insulin pump therapy for over 25 years, and continuous glucose monitoring (CGM) for about 6 years. 



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Submitted by Sheila Green (not verified) on

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I have had type 1 for 61 years .... I would like to be given a voice in the Type 1 community to help others understand the disease . I am 64 years old with no major complications . I have so much experience to talk about.
Sheila Green

Submitted by Janice Johnston (not verified) on

In reply to by Sheila Green (not verified)

I'm 58 & was diagnosed with Type 1 in 1999(17yrs ago). I use an insulin pump, but am not satisfied with the CGM, as I am not convinced of the accuracy of BG #s I was retrieving or felt confident enough in these results to bolus using those results.
Sheila, I would love to communicate with you regarding your experiences.

Submitted by LOOP Blog Editorial on

In reply to by Janice Johnston (not verified)

Janice, I’m sorry to hear that you’re not satisfied with your CGM. I would like to have you chat with a member of our HelpLine team to see if they can help and will share you information with them. Also, please know that the information provided by CGM systems is intended to supplement, not replace, blood glucose information obtained using a home glucose meter. A confirmatory fingerstick is required prior to making adjustments to diabetes therapy.

Submitted by Lynne Marie Pe… (not verified) on

In reply to by Janice Johnston (not verified)

Janice - Sorry to hear you are not happy with your CGM, I love mine. I still test my blood more than the 2 times per day that the CGM requests me to do. I have gotten my A1C down to 6.1% & feel more confident than ever knowing that the CGM will notify me when I'm over or under the limits set on my CGM. This has helped me tremendously keep a tighter rein on my Blood Sugars.

Submitted by Greg Streeter (not verified) on

In reply to by Sheila Green (not verified)

I have had type1 for 55 years... I con not say no major side effects. I still live a normal productive life. I have stories to tell too...

Submitted by Lynne Marie Pe… (not verified) on

In reply to by Sheila Green (not verified)

I have had Type 1, Autoimmune Diabetes since 1961. I would be very interested in speaking with those that have had long time, Type 1 Diabetes.
Lynne Marie :-)

Submitted by LOOP Blog Editorial on

In reply to by Lynne Marie Pe… (not verified)

Lynn Marie, we have several MiniMed Ambassadors who have lived with diabetes for a long time and who have volunteered to speak with others. You can learn more about our MiniMed Ambassador program and our Amabassadors here – www.minimedambassadors.com.

Submitted by Linda Charlton (not verified) on

In reply to by Sheila Green (not verified)

I became a type 1 at age 57. I really struggle with control. If I give before I eat, I get busy and don't eat or forget to dose afterward. Got suggestions?

Submitted by LOOP Blog Editorial on

In reply to by Linda Charlton (not verified)

Linda, this is a great question for the community to see how others manage this. We also have many customers who participate in our MiniMed Ambassador program who have volunteered to share their experiences on how they handle situations just like this. You can learn more about our MiniMed Ambassadors and connect with one of them here – www.minimedambassadors.com.

Submitted by Dr. Bradley Sakran (not verified) on

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I agree with your blog. Emotional changes do occur with changes in blood sugar levels. I have had type 1 diabetes over 50 years and have personally experienced these emotional roller coaster. Also I have seen this in my patients. Good article

Submitted by Ron Nole (not verified) on

In reply to by Commenter (not verified)

Thank you Sara. I can sure relate. I didn't know highs could have that effect. No word yet on the (better check bg, can't remember) device for your cell phone which only works with Apple and not Android?

Submitted by LOOP Blog Editorial on

In reply to by Ron Nole (not verified)

Hi Ron, we’re currently working on Android compatibility for MiniMed Connect. We will be sure to share an update with the community once this is ready. Thank you for your patience while we work on this.

Submitted by Hilda Mori (not verified) on

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I have diabetes #2

Submitted by Rebecca (not verified) on

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Can you factor in when a type 2 diabetic is also an alcoholic ? What happens then? Concerned about my sister; her emotions are all over the map. She uses an insulin pump to counteract the alcohol.

Submitted by LOOP Blog Editorial on

In reply to by Rebecca (not verified)

Hi Rebecca, this sounds like it would be a great question for your sister's healthcare team as they are in the best position to address her individual needs. If your sister has any specific questions related to her Medtronic device, please have her contact us at 800-646-4633 and press Option 1 for help.

Medtronic Diabetes Clinical Manager Gina, who has lived with type 1 diabetes for more than 39 years, addresses the affect blood sugar levels can have on your everyday emotions. Where is this information?

Submitted by peg (not verified) on

In reply to by Commenter (not verified)

It works the other way also. If I am excited or upset about something it can send my BS soaring. Also if I am thinking hard(especially being creative) my BS plummets. It is a wonder we can make any sense of it all.

Submitted by PC (not verified) on

In reply to by peg (not verified)

VERY, VERY TRUE! Same with me.

Submitted by Lisa DiLorenzo (not verified) on

In reply to by Commenter (not verified)

My 2 sons (26, 28) and I are type 1 diabetics and this is sooooo true. In fact we do have a sense of humor. Any time anyone in the house is crabby the phrase is "go check your sugar".

I have been a type 1 diabetic for 9 years now and I have definitely had this happen on many occasions. Blood glucose levels do indeed affect emotions.

Submitted by Educate Teachers (not verified) on

In reply to by Commenter (not verified)

My son was in middle school last year and with all other things going at this point in his life, his sugar levels play a big role in his attitude at school. Most teachers understand my concerns that his blood sugars play a role in how he reacts and how well he does in school. The school nurse is his biggest advocate while he his there. When he acts out of the "norm", he is either too high or too low. However; one particular teacher will not "tolerate" anything but normal. It has made his being in her class the reason he doesn't want to go to school. Its his homeroom and first period so this sets the tone for the day....... downhill. We have had several meetings with the school and her but nothing good ever came of it (retaliation from her). He has recently started the CGM in December and we have seen a major difference in his grades the past month. I do believe there are better because he can monitor his BG more closely. Sorry for the soapbox speech but how she treated him his whole school year was very disheartening.
As with Lisa, when he is short with anyone the first thing out of our mouth is "go check your blood, I believe your BG is high".

Submitted by LOOP Blog Editorial on

In reply to by Educate Teachers (not verified)

Thank you for sharing with the community, Robin. We agree it’s important to educate teachers. A blog you may find interesting is 10 Tips for Teachers of Students with Diabetes which you can find here - http://www.loop-blog.com/10-tips-for-teachers-of-students-with-diabetes/.

Submitted by Melinda (not verified) on

In reply to by Commenter (not verified)

My 17 year old son is a type 1 diabetic also. He's only had the disease for 4 years. He's really the most laid back, easy-going teenage boy I've ever known, so when he starts getting grumpy or mouthy or just plain obstinate and emotional, are go-to response is, "Check your blood sugar." 9 times out of 10, he's high. As if normal teenage hormones and emotions aren't enough to deal with...

Submitted by Roger Schmurr (not verified) on

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Peg is right on. Anger, excitement, watching a good sports event—all such things send my blood sugar sky high. It's difficult to counter that while in process, but I trust my CGM enough to bolus afterwards.

Submitted by P . Hays (not verified) on

In reply to by Commenter (not verified)

Why have there been so many new medications created for type 2 diabetics while type 1 diabetics have either shots or a pump. It's been 40 years. Still waiting for a type 1 cure. They're curing cancer. Just curious.

Submitted by Sue (not verified) on

In reply to by Commenter (not verified)

My husband has been a type 1 diabetic for 30 years now. He has been put on suspension from work for yelling at an employee of his. He was told he was too aggressive. He has to have a 30 minute dinner break required by law but since he is the only supervisor working his shift he has no time to take it. This causes his sugers to go too high or low with a high stress level job. They will let them know next week if he still has a job. He's been working his position for 37 years,perfect attendance! People don't know what high and low sugers do to a person!

Submitted by LOOP Blog Editorial on

In reply to by Sue (not verified)

Sue, I’m very sorry to hear this. Please know that you and your husband are in our thoughts.

Submitted by Debbie Rauch (not verified) on

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This is so true. I get very irritable when my blood sugar is low. I have had Type 1 Diabetes for 37 years. I just started using A CGM and I really love it. I had Gastric bypass 2 years ago and lost 70 lbs. But I still feel hungry all the time and crave carbs like crazy. I have always been a stress eater. I have always felt like I have had an addiction to carbs. I am constantly battling with my eating and my blood sugars. It is a great source of stress and frustration for me.

I have had diabetes type 2 for 8 years now and have a pump I react to highs and lows in the same way grumpy and critical of others it is hard to find a happy meden way to Treat others but I try to always work at it and take and check bg as often as I can and treat it according to what is Nessasay.

Hi my friend has diebeaties 1 and he is 46 years old, why does he get so moody and angry just about every day. Why does he take it out on me when I'm home. I wish he would look after his self. I have known him for 10 years. He is a nice guy when he's not feeling sick. I wish he was good again. How do I get him to look after his health again? He used to play sport. Now he just sits around the house. I know that he is feeling sick but he doesn't want to do anything with anyone. He uses to be different once.

Mood swings may be associated with PMS, peri-menopause
or menopause, and although they are not causing for medical alarm, they sure can make it hard on both the sufferer and those nearby. It's important to note, however, that because mood changes can be a sign of another medical condition or mental health problem, you should always seek a doctor's help in dealing with them.

Submitted by Jeff Peters (not verified) on

In reply to by Commenter (not verified)

My nature is to try to be successful as I have a very active and inventive mind. I dream up things all the time. Working in petrochemical products and processes I am familiar with. Due to no way to develop profitable products, I can get so excited and so disappointed as my sugar levels as a diabetic are very out of sinc many times as over done attitude, cranky, obnoxious attitudes, I am a terror. I have just found out what the problem and causes there are. Currently looking at my skin conditions. Eczema, etc.

Submitted by L J Richmond (not verified) on

In reply to by Commenter (not verified)

My husband has type 2 diabetes and doent' keep a close eye on his bsl. Because of this are marriage is suffering. When I speak to him he thinks I'm talking to him rudely I've been trying to be conscious of the way I talk and the tone of my voice. I've tried to suggest he check his bsl, but he continues to believe it all me. I'm starting to think I'm crazy. Please I need some good advice. Also he is under a lot of stress.

According to the article, why does the brain's need for glucose play a significant role in mood changes related to blood glucose levels?

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