If you experience a racing heart and dizziness within one to three hours after eating, you may have a condition called reactive hypoglycemia. Reactive hypoglycemia, also referred to as postprandial hypoglycemia, is characterized by a drop in blood sugar, usually below 70 mg/dL. While most cases of hypoglycemia are associated with diabetes, reactive hypoglycemia usually occurs in individuals without diabetes.
The National Diabetes Information Clearinghouse notes that the exact cause of most cases of reactive hypoglycemia cannot be identified. One theory suggests that people prone to reactive hypoglycemia may not release the hormone glucagon, which serves as a backup source of energy, correctly. Another theory is that people who experience reactive hypoglycemia are overly sensitive to epinephrine, which causes the symptoms associated with hypoglycemia.
Stomach surgery can also increase the chance of experiencing reactive hypoglycemia. In some individuals who have had prior stomach surgery, food passes more quickly through the stomach and into the small intestine. As a result, blood sugar drops.
The symptoms of reactive hypoglycemia occur as a result of a lack of glucose in your brain. In addition to a racing heart and dizziness after eating, someone with reactive hypoglycemia may experience hunger, confusion, weakness, light-headedness, shakiness, anxiety and confusion. Some people also experience blurred vision and muscle tremors.
Treatment and Prevention
Most people with reactive hypoglycemia do not require medical treatment and can control blood sugar levels by making some changes in eating habits. Eating a series of small meals or snacks throughout the course of the day, instead of three or fewer large meals, can provide your body with a steady supply of glucose and help keep your blood sugar levels steady. Aim to eat five or six times per day. It is also important to pay attention to what you eat. Each meal or snack should contain a balance of carbohydrates, lean protein and a small amount of fat. You should also include high fiber foods, such as beans, fruits, vegetables and whole grains, which move through your digestive system slowly and keep your blood sugar levels steady.
MayoClinic.com notes that it is important to engage in regular physical activity. The best time to exercise is directly after a meal or after a snack that contains carbohydrates. This ensures that your body has enough glucose to provide energy to sustain your physical activity.
It is also important to drink plenty of fluids, especially when increasing your fiber intake. Aim to drink at least eight glasses of water per day. Limit caffeinated beverages, such as coffee, tea and soda, to no more than two per day. Avoid alcohol, which directly lowers your blood sugar.