Blood sugar, also known as glucose, represents the main sugar found in the bloodstream, serving as the body’s primary energy source. This glucose originates from the food consumed and is transported to cells throughout the body to fuel various functions. The body possesses intricate mechanisms to manage these glucose levels, ensuring they remain within a healthy range.
How Your Body Processes Sugar
When carbohydrates are consumed, the body digests them, breaking them down into glucose. This glucose is then absorbed into the bloodstream, leading to a rise in blood glucose levels.
In response to this increase, the pancreas releases a hormone called insulin. Insulin acts as a “key,” allowing glucose to enter cells for immediate energy.
Excess glucose is stored as glycogen, primarily in the liver and muscles, for later use. As glucose moves from the bloodstream into cells, blood sugar levels begin to decrease, prompting the pancreas to reduce insulin production.
What Affects How Long Sugar Stays
The type and quantity of carbohydrates consumed play a significant role, with simple sugars often causing quicker and higher spikes compared to complex carbohydrates with fiber. Physical activity is another important factor, as exercise helps cells absorb glucose from the blood more efficiently.
Individual metabolic differences and insulin sensitivity also impact how effectively the body uses insulin to clear glucose from the blood. When cells are less sensitive to insulin, glucose remains in the bloodstream for longer periods. Hydration levels can also affect blood sugar regulation, as dehydration can concentrate blood sugar.
Stress and sleep patterns significantly influence blood sugar. Stress triggers the release of hormones like cortisol, which can cause the liver to produce more glucose, leading to elevated blood sugar levels. Insufficient or poor-quality sleep can reduce insulin sensitivity, making it harder for the body to use insulin effectively, and can also increase cortisol levels.
Underlying health conditions, such as diabetes, fundamentally alter this process. This can be due to insufficient insulin production or the body’s inability to use insulin properly, resulting in persistently high blood sugar.
Interpreting Blood Sugar Readings
For individuals without diabetes, a fasting blood sugar level (after at least eight hours without food) typically falls between 72 to 99 mg/dL (4.0 to 5.4 mmol/L). Two hours after eating, blood sugar levels for non-diabetic individuals are generally below 140 mg/dL (7.8 mmol/L).
Temporary increases in blood sugar after meals are a normal physiological response as the body processes consumed carbohydrates. However, very high blood sugar, known as hyperglycemia, can manifest with symptoms like frequent urination, increased thirst, and blurred vision. Conversely, very low blood sugar, or hypoglycemia, can lead to symptoms such as shaking, sweating, and dizziness.
Health Impacts of Persistent High Sugar
Persistent high blood sugar, often associated with prediabetes or type 2 diabetes, can lead to various long-term health complications. Chronic high blood sugar can progressively damage blood vessels and nerves throughout the body. This persistent elevation increases the risk of cardiovascular diseases, including heart attack and stroke.
Organ systems can also be affected, leading to kidney damage, which may eventually require dialysis or a kidney transplant. Nerve damage, known as neuropathy, can cause pain, numbness, or loss of sensation, particularly in the hands and feet. Additionally, chronic high sugar can harm the eyes, potentially leading to vision problems or even blindness.
Maintaining healthy blood sugar levels is therefore important for protecting overall health and preventing these complications.