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Here's Why Low Blood Sugar Makes You So Cranky

Expert shares what to know about low blood sugar and signs you have it. 

Your body relies on blood sugar for its main source of energy and when it's low, it's common to experience a range of highs and lows that are not typical to your normal behavior. You can feel like you're on a rollercoaster of emotions, so managing your blood sugar is vital for your mood and overall well-being. Eat This, Not That! Health spoke with Dr. Julie Barrette, MS, RD, a senior clinical dietitian, nutrition care services at Providence Mission Hospital who shares what to know about blood sugar, signs it's too low and why your mood changes. Read on—and to ensure your health and the health of others, don't miss these Sure Signs You've Already Had COVID.


What to Know About Blood Sugar

eating dinner

Dr. Barrette tells us, "Blood sugar, or glucose, is the main sugar found in our blood. This sugar comes from the food that we eat – it provides nutrients and energy to the body's organs, muscles and nervous system. It's important to know that your body relies on keeping a healthy blood sugar range to prevent or delay long-term, serious health problems such as vision loss, kidney disease or heart disease. Plus, it can help improve your energy and mood!  The standard range of blood sugar levels for a non-diabetic person tends to fall between 70–99 mg/dl, which is considered normal. Someone who has diabetes can have their blood sugar range from 80 mg/dl to 130 mg/dl.This level fluctuates throughout the day depending on when you eat and also when you check your blood levels."   


Causes of Low Blood Sugar

Doctor with glucometer and insulin pen device talking to male patient at medical office in hospital.

Dr. Barrette says, "Low blood sugar is called hypoglycemia – it can happen when your blood sugar level is lower than what is considered normal. Glucose is your body's main energy source, which is why it's important to make sure to get your levels back to normal as quickly as you can.  Low blood sugar has a myriad of causes, which differ from person-to-person. Someone with diabetes might also experience different causes compared to another diabetic – causes can include missing a meal, taking too much insulin, excessive exercising, hot and humid weather and drinking alcohol." 


Why Low Blood Sugar Changes Your Mood and Makes You Cranky

Woman suffering an anxiety attack alone in the night

According to Dr. Barrette, "Low blood sugar can mimic the symptoms of anxiety, which I find very interesting.  When your blood sugar level keeps dropping, the body attempts to normalize the levels by increasing the flow of adrenaline. This triggers a "fight or flight" response, according to the British Journal of Pharmacology. Adrenaline makes your heart race and your palms sweat, but it can also make you feel cranky and anxious."


Why Someone May Not Know They Have Low Blood Sugar


"Typically, hypoglycemia symptoms occur when blood glucose levels fall below the normal 70 mg/dL level," says Dr. Barrette. "However, hypoglycemia unawareness, or when your blood glucose drops below normal without signs or symptoms, can also happen.  People who experience hypoglycemia unaware cannot tell when their blood glucose drops below the normal level – that's why many don't immediately contact their doctor. It's important to understand that hypoglycemia unawareness can put you at an increased risk for severe low blood glucose, which can cause confusion or disorientation, convulsions, seizures, loss of consciousness, or coma."


Low Blood Sugar is Dangerous if Left Untreated


Dr. Barrette explains, "Hypoglycemia is not a disease but can be an indication of other underlying health issues. If left untreated, it can lead to more serious conditions, such as death. That's why it's crucial to treat your low blood sugar right away, no matter the cause.  If you experience frequent low blood sugar episodes, keep a record of your symptoms, and talk to your doctor about any patterns that you might see. Your doctor can suggest ways to prevent or avoid low blood sugar attacks in the future. They can also help to determine if you need further treatment." 


Signs You Have Low Blood Sugar


Dr. Barrette says the following four signs are warning signals your body is sending you that indicate your blood sugar is low. 

–"Nervousness or Anxiety 

The body responds to low blood sugar and anxiety in the same way. If you are worried your anxiety symptoms might be caused by hypoglycemia, make an appointment with your doctor as soon as possible.  

–Shaking and sweating Hypoglycemia triggers the release of hormones, such as epinephrine and norepinephrine – your body relies on them to raise blood sugar levels. The release of these hormones can cause other symptoms such as tremors, sweating, rapid heartbeat, anxiety, and hunger. 


When your low blood sugar drops below normal levels, your body tries to reserve as much energy as possible, including your brain. This can make you feel lightheaded or confused, according to Harvard Medical School. Taking a sip of juice can help relieve the symptoms. If you continue to experience dizziness, make an appointment with your doctor immediately.  


Your body reacts to low blood sugar by releasing stress hormones, such as epinephrine – it is responsible for hunger. Unlike other parts of the body, our brain needs glucose to function properly. Releasing hormones that cause hunger is your body's way of telling you it needs help."


How to Help Stabilize Blood Sugar and Your Mood

Mature african woman practicing yoga and meditates near swimming pool outdoor

The University of Michigan School of Public Health states, "Several lifestyle principles can help stabilize blood sugar:

–Reduce and manage stress. Stress has been shown to negatively affect the regulation of blood glucose. Specifically, hormonal changes during acute and chronic stress can affect glucose balance.

–Increase intake of protein and fiber. Protein has a low glycemic index (GI), which means they have a low impact on blood sugar levels. Fibrous foods are also shown to have a lower GI value when compared to their refined counterparts.

–Reduce intake of sweet beverages and refined carbohydrates. A diet high in refined carbohydrates, including sweet beverages, has a high GI value and is associated with unstable blood sugar regulation

Although more studies are warranted to solidify the relationship between mood and blood sugar, considering dietary and lifestyle implications on common mood disorders can rule out lesser known causes."


Heather Newgen
Heather Newgen has two decades of experience reporting and writing about health, fitness, entertainment and travel. Heather currently freelances for several publications. Read more about Heather
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