It's normal for glucose levels fluctuate throughout the day, based on your diet, activity level, medication and emotional state. Typically, glucose is higher after eating and should return to normal ranges within two to four afters after your meal. Sometimes you may experience hypoglycemia -- or low blood sugar -- soon after eating. If you're hungry, nervous, anxious, dizzy, shaky or sweaty, you may have hypoglycemia, the National Institute of Diabetes and Digestive and Kidney Diseases warns.
Glucose Basics
Glucose is your body's preferred energy source. Food you eat is converted to glucose during digestion and released into your bloodstream. Your pancreas releases insulin, which transports the glucose into your cells for use. People with diabetes may not produce insulin or their bodies may not use insulin effectively. If you have too much insulin in your bloodstream, you'll have low glucose levels. Hunger is usually the first symptom of low blood sugar. For people with diabetes, you'll want a blood sugar level between 70 and 130 mg/dL before eating. After eating, your blood sugar will rise, but should drop below 180 mg/dL within two hours, and back to your pre-meal level four hours after eating. You should be ready to eat again every four to five hours.
Drug-Induced Hypoglycemia
According to the National Institutes of Health, certain drugs can cause low blood sugar at any time. Beta-blockers, MAO inhibitors and quinine can all cause low glucose levels. The most common drugs to cause low blood sugar levels are the medications designed to treat diabetes. Taking too much insulin, metformin or other drugs that help to manage diabetes can lead to hypoglycemia. Both the amount and the timing of your diabetes medication are important for controlling your glucose level. If you're experiencing hypoglycemia, drink 15 g of carbohydrates, such as 4 oz. of juice or soda or 8 oz. of milk and wait 15 minutes for the symptoms to pass. If your glucose is still too low, consume an additional 15 g of carbohydrates and recheck your glucose level in another 15 minutes.
Reactive Hypoglycemia
People who don't have diabetes may experience reactive hypoglycemia -- low blood sugar one to three hours after eating. Reactive hypoglycemia may be caused by a hormone called epinephrine or by a glucagon deficiency. Gastric bypass surgery can also cause reactive hypoglycemia because food passes so quickly through your digestive system. The NIDDK recommends eating small, high-fiber meals every three hours, avoiding sugary foods and starchy vegetables that can cause a spike and dramatic drop in blood sugar, and staying physically active.
Preventing Low Glucose Levels After Eating
Fortunately low blood sugar is easy to treat -- you often just need to eat or drink something that your body can quickly convert to glucose. Although the symptoms of hypoglycemia are unpleasant, they're rarely serious -- but you may not want to drive if you have low blood sugar, which can make it difficult to focus. You can prevent hypoglycemia by eating enough food at meals; sticking to a regular schedule for eating and exercising, taking the proper amount of insulin or other diabetes medication, limiting alcoholic beverages and carefully monitoring your glucose levels. If you have chronic low blood glucose, you may need to adjust your diabetes treatment plan to lower insulin dosages or include more food.
