5 Sneaky Signs Your Blood Sugar Is Too Low

Your body and brain run on glucose for fuel. So, when blood sugar drops, it can feel like things have come to a grinding halt. This is your body’s way of telling you, “Hey, I need help—stat!” 

Medically speaking, low blood sugar, or hypoglycemia, is when blood sugar falls below 70 mg/dL.  It most commonly occurs in people with type 1 diabetes. “Low blood sugar is uncommon in people without diabetes, but it can be quite common—and potentially dangerous—for those who do [have diabetes],” says Samantha Cassetty, M.S., RD. However, some people without diabetes may be genetically prone to a form of low blood sugar known as reactive hypoglycemia, especially if they have a family history of diabetes or obesity. Low blood sugar can also be caused by certain medications, eating disorders, some types of tumors and weight-loss surgery. 

Read on to learn how to know how to tell if you have low blood sugar, plus dietitian-tested strategies to protect against hypoglycemia.  

1. You Feel Dizzy, Lightheaded or Can’t Concentrate

When your body doesn’t get the glucose it needs from food, it can’t supply your brain with the energy it needs to function properly. This creates myriad symptoms, often leaving you feeling dizzy, lightheaded or having trouble concentrating, says Cassetty. “This is one of the more common red flags that your blood sugar is dipping too low. It’s your body’s way of saying, hey, I’m running out of energy!” she adds.

2. You’re Suddenly Shaky, Anxious or Irritable

“Your mental functioning is directly impacted by the amount of fuel your brain has to process and respond to emotions and situations clearly,” says Cassetty. When your brain doesn’t receive the glucose it needs, it releases the hormone adrenaline to tell the body that something isn’t right. “Blood-sugar swings can affect your mood and even mimic anxiety symptoms,” she says. If you’re noticing your mood is swinging back and forth like a pendulum, it could be your blood sugar talking. 

3. Your Heart Starts Racing 

That adrenaline also stimulates your body’s flight-or-fight response to bring blood sugar back up to normal levels. This may lead to a rapid heartbeat and an increase in blood pressure. “For those with a chronic condition, like high blood pressure, as well, they should be especially cautious of this side effect,” says Meme Inge, M.S., RDN.

4. You Feel Nauseated for No Apparent Reason

It may seem ironic that nausea may be a side effect of low blood sugar. However, research has found that nausea can be a mild yet disruptive side effect of hypoglycemia. To complicate matters, this unpleasant side effect may seemingly come out of nowhere, says Inge. Not everyone experiences it, though. According to an older study, hypoglycemia-related nausea is more likely to occur in people on diabetes medication. Additionally, those with diabetes are also more prone to a condition called gastroparesis, which results in delayed stomach emptying, potentially leading to nausea. 

5. You’re Inexplicably Hungry

This may seem like a no-brainer. But when your body doesn’t get the fuel it needs, you’re going to experience hunger as a result. Here’s why. When your body doesn’t have enough fuel on board, it releases the hunger hormone ghrelin. This tells your body you need to eat while your brain shouts, “I need sugar, now!” You may also notice an increased desire for sweet foods, says Inge. “This is your brain’s way of telling your body you need glucose immediately. After all, your brain is counting on that sugar to fuel its many processes!” she says. 

Strategies for More Stable Blood Sugar

Here are science-backed strategies Cassetty and Inge share with their clients for more stable blood sugar:

• Pair carbohydrates with protein or healthy fats. This dynamic duo helps slow digestion and promotes steadier blood sugar. So, think healthy, balanced snacks like nuts and fruit or a little cheese with a handful of whole-grain crackers. 
• Load up on fiber-rich foods. Fiber naturally slows digestion for a smooth, steady glucose release. “Rather than cutting carbs, focus on wholesome, whole food, fiber-rich options, and pair them with proteins and fats,” says Cassetty. Beans, lentils, vegetables, berries, whole grains and seeds all help regulate blood sugar, she says. 
• Eat regularly throughout the day. In most cases, hypoglycemia occurs roughly two to five hours after a meal. So, it’s extra important to eat at regular intervals and avoid meal skipping. “A routine with eating times can be helpful so you don’t skip meals accidentally and go too long without food,” says Inge. 
• Enlist the 15/15 rule. “If you have diabetes and experience low blood sugar, it’s important to treat it right away using 15 grams of fast-acting carbohydrates, like juice or glucose tablets,” says Cassetty. “Then recheck your blood sugar after 15 minutes.”
• Know the danger signs. Severe low blood sugar, which is a blood glucose level less than 54 mg/dL, is a medical emergency. If you monitor your blood glucose and see it’s headed in this direction, don’t wait to treat it. 
• Keep your health care professional in the loop. If you suspect you’re experiencing hypoglycemia, it’s important to touch base with your health care professional, especially if you’re living with diabetes. 

Our Expert Take

Low blood sugar, or hypoglycemia, occurs when blood glucose levels fall below 70 mg/dL. Because hypoglycemia has a long list of symptoms, it’s not always easy to recognize. Some sneaky signs of low blood sugar include feeling dizzy, lightheaded, nauseous, shaky, irritable and hungry. You may also have a rapid heartbeat or have difficulty concentrating.  Hypoglycemia most commonly strikes people with type 1 diabetes. However, it can also happen to those with type 2 diabetes who take insulin, people with reactive hypoglycemia, or those with certain health conditions or who have had weight-loss surgery.  

If you’re prone to low blood sugar, eating regularly throughout the day and focusing on a balanced diet rich in fiber, complex carbohydrates, lean proteins and healthy fats may help. At the extreme, severe hypoglycemia is a medical emergency and requires prompt treatment. If you suspect you’re experiencing low blood sugar, be sure to discuss it with your health care professional, who can help you develop strategies to manage this condition.