When a person with diabetes gets the shakes, it almost always means their blood sugar has dropped too low, a condition called hypoglycemia. This is defined as blood glucose falling below 70 mg/dL. The shaking itself is your body’s alarm system firing off, and it’s a signal to act quickly.
Why Low Blood Sugar Causes Shaking
When blood sugar drops below 70 mg/dL, your body treats it as an emergency. It floods your system with adrenaline and noradrenaline, the same stress hormones that kick in during a fight-or-flight response. These hormones are trying to push stored sugar back into your bloodstream, but they also trigger a wave of physical symptoms: trembling hands, a pounding heart, sweating, anxiety, and sudden intense hunger.
The shaking is essentially your muscles responding to that surge of adrenaline. It’s the same kind of tremor you might feel if you were suddenly startled or extremely anxious, except in this case it’s being driven by your body’s detection of dangerously low fuel.
Other Symptoms That Come With It
Shaking is usually one of the first signs, but it rarely shows up alone. The adrenaline-driven symptoms tend to hit together: trembling, sweating, a fast heartbeat, tingling around the mouth or fingertips, and a feeling of nervousness or dread. You might also feel ravenously hungry.
If blood sugar keeps falling below 54 mg/dL, a second set of symptoms appears. These come from your brain not getting enough glucose to function properly: confusion, difficulty thinking, weakness, unusual warmth, and fatigue. At its most severe, this can progress to seizures or loss of consciousness. The adrenaline symptoms are your warning window. The brain-related symptoms mean you’re already in more dangerous territory.
Three Levels of Low Blood Sugar
The American Diabetes Association classifies hypoglycemia into three levels that are useful to understand:
- Level 1: Blood glucose between 54 and 69 mg/dL. This is where the shakes, sweating, and hunger typically start. You can treat it yourself.
- Level 2: Blood glucose below 54 mg/dL. Brain-related symptoms like confusion and weakness begin. This requires immediate action.
- Level 3: A severe episode where you need someone else’s help to recover, regardless of the specific glucose number. This can involve seizures, loss of consciousness, or an inability to think clearly enough to treat yourself.
Which Diabetes Medications Raise the Risk
Not all diabetes treatments carry the same risk of causing the shakes. Insulin is the most common culprit, especially if the dose is slightly too high, a meal is skipped, or physical activity burns through glucose faster than expected.
Among oral medications, sulfonylureas carry a notably elevated risk. One large study found that people taking sulfonylureas were nearly three times more likely to experience hypoglycemia compared to those taking metformin. Metformin on its own rarely causes low blood sugar. If you’re on a sulfonylurea and getting the shakes frequently, that’s worth discussing with whoever manages your diabetes care, because there may be alternative options with a lower hypoglycemia risk.
Less Common Causes of Shaking
While low blood sugar is by far the most likely explanation, it’s not the only possibility. During diabetic ketoacidosis, a serious complication of very high blood sugar, the body can lose critical minerals like magnesium, potassium, and calcium. Magnesium deficiency in particular can cause tremors, muscle spasms, and agitation. These symptoms overlap with hypoglycemia, which is why checking your blood sugar when the shakes hit is so important. If your glucose reads normal or high and you’re still trembling, something else is going on.
How to Treat the Shakes Right Away
The standard approach is called the 15-15 rule: eat or drink 15 grams of fast-acting carbohydrates, wait 15 minutes, then check your blood sugar. If it’s still below 70 mg/dL, repeat. Keep going until your levels are back in your target range, then follow up with a balanced snack or small meal that includes protein to keep your blood sugar stable.
Good options for those 15 grams of fast-acting carbs include:
- 4 ounces (half a cup) of juice or regular soda
- 1 tablespoon of sugar, honey, or syrup
- 3 to 4 glucose tablets
- 1 tube of glucose gel
- Hard candies or jellybeans (check the label for the right amount)
Skip chocolate, baked goods, or high-fiber foods in the moment. The fat and fiber slow down sugar absorption, which is the opposite of what you need when your blood sugar is already low.
If someone with diabetes is shaking and becomes confused, loses consciousness, or can’t swallow safely, they should not be given food or drink. This is when emergency glucagon, available as an injection or nasal spray, becomes necessary. Trying to feed someone who can’t swallow properly risks choking or aspiration.
When the Warning Signs Disappear
One of the more dangerous things that can happen over time is called hypoglycemia unawareness. After repeated low blood sugar episodes, the body’s adrenaline response starts to weaken. The shakes, sweating, and racing heart become muted or disappear entirely. Your blood sugar can drop to dangerously low levels without any of the usual warning signals.
This happens because previous episodes of hypoglycemia blunt the hormonal response to the next episode. It’s a vicious cycle: frequent lows cause unawareness, and unawareness leads to more severe lows because you don’t catch them early. People with hypoglycemia unawareness face a dramatically higher risk of severe episodes. For those with type 2 diabetes, the risk of a severe low requiring outside help increases 17-fold. For type 1 diabetes, it’s about six-fold. Severe episodes can result in seizures, coma, falls leading to fractures, heart rhythm problems, and in rare cases, death.
If you’ve noticed that you no longer feel the shakes before a low blood sugar reading shows up on your meter, or if others are noticing symptoms in you before you feel anything, that’s a significant change worth addressing. Carefully avoiding low blood sugar for several weeks can sometimes restore the body’s ability to produce warning symptoms again.
Practical Steps to Reduce Episodes
Frequent shaking episodes are a sign that something in your diabetes management needs adjusting. Common triggers include skipping or delaying meals, exercising more than usual without adjusting food or medication, taking too much insulin, or drinking alcohol on an empty stomach. Keeping fast-acting carbohydrates within reach at all times, whether in a bag, car, desk, or nightstand, means you’re always prepared to treat a low quickly. A continuous glucose monitor can also catch dropping levels before symptoms start, which is especially valuable for people who’ve lost their early warning signs.