Does a Cold Cause an Increase in Blood Sugar?

Colds can cause discomfort in the body, and they often manifest with symptoms such as headache, nasal congestion, and physical weakness. High blood sugar is a common manifestation associated with colds.

Blood Sugar Elevation during a Cold

The question of whether a cold can cause an increase in blood sugar actually boils down to issues related to human metabolism. When the body is infected, it produces a stress-induced rejection response against microorganisms, manifesting as a strong resistance reaction against external microbes. To mobilize this response, the body must raise blood sugar levels to provide energy, resulting in elevated blood sugar after a cold. This elevation is particularly evident in individuals who have previously been diagnosed with diabetes. Therefore, during a cold, especially for diabetic patients, it is important to monitor blood sugar levels closely as they may rise, necessitating a corresponding increase in the dosage of insulin or hypoglycemic medications.

Definition of High Blood Sugar

High blood sugar generally refers to an increase in the glucose content in the blood. Normal fasting blood sugar levels are below 6.1mmol/L, and normal postprandial blood sugar levels 2 hours after eating are below 7.8mmol/L. Levels above this range are considered high blood sugar. High blood sugar can be classified as physiological or pathological.

Physiological hyperglycemia can be observed 1 to 2 hours after a meal, or when there is increased adrenal secretion due to emotional stress. Pathological hyperglycemia can be caused by endocrine dysfunction leading to diabetes, intracranial hypertension due to cranial trauma, intracranial hemorrhage, or meningitis, dehydration, acute or chronic pancreatitis, liver dysfunction, and other conditions.

Common Causes of High Blood Sugar

1. Physiological or temporary blood sugar elevation can occur 1 to 2 hours after a meal, after glucose injection, due to increased adrenal secretion caused by emotional stress, or after injection of epinephrine.

2. Pathological hyperglycemia can be caused by:

• Islet dysfunction: Insufficient insulin secretion, either relatively or absolutely.
• Increased secretion of hormones that raise blood sugar: such as hyperpituitarism, hyperadrenocorticism, hyperthyroidism, chromaffinoma, and insulinoma.
• Dehydration: Vomiting, diarrhea, and high fever can cause mild elevations in blood sugar.
• Others: Conditions such as anesthesia, asphyxia, infection, epilepsy, and eclampsia.