High blood sugar or hyperglycemia is a sign of diabetes and is described as fasting blood glucose levels above 7 mmol/L and after-meal blood glucose levels above 10 mmol/L. Persistently elevated blood sugar results in the narrowing of blood vessels, which impairs blood flow to different organs and tissues of the body. This may lead to complications related to malfunctioning of the vessels. Following is a list of conditions most commonly associated with unmanaged high blood glucose levels.
1. Macrovascular complications (pertaining to big blood vessels):
a. Stroke
Persistently high blood sugar levels, especially in the presence of high blood pressure and high cholesterol, may lead to impaired blood circulation in the brain and possibly stroke.
b. Heart disease and high blood pressure
Increased blood sugar in the vessels reduces the production of nitric oxide (a substance known to dilate the vessels). Consequently, blood pressure increases over time and manifests as high blood pressure and can lead to heart diseases.
c. Peripheral vascular diseases
Through the mechanism explained above, the blood pressure in the peripheral parts of the body also increases, such as in the arms and the legs. This may lead to peripheral vascular diseases. An example is intermittent claudication.
2. Microvascular complications (pertaining to small blood vessels):
a. Eye damage and cataracts
High blood sugar is the most common cause of eye conditions and blindness. Uncontrolled blood glucose can damage eye functioning and may result in cataracts, glaucoma, bleeding, and fluid accumulation, etc. Maintaining blood sugar levels, blood pressure, and cholesterol within a normal range can, however, help reduce the risk.
b. Kidney damage
Uncontrolled blood glucose damages the kidneys over time. Diabetes is reported to be the leading cause of kidney disease and dialysis. Nevertheless, damage can be avoided if blood sugar is lowered to appropriate levels.
c. Nerve damage
Diabetes is also known to cause nerve damage if not adequately managed. Some examples are nerve pain, muscle weakness, tingling and burning sensations, delayed stomach emptying, and numbness.
d. Diabetic foot
Diabetic foot is a very common complication of diabetes. It happens as a result of poor blood circulation of the foot tissues, which increases the risk of infections and skin wounds. In addition, nerve damage in the area leads to numbness and it may further worsen the condition. People with diabetes are recommended to have foot examination done professionally at least once every year. Self-monitoring is also encouraged.
In order to avoid these complications, it is very important to keep blood sugar levels under control. For someone who is diagnosed with diabetes, the normal fasting glucose target is 4-7 mmol/L and, random or after-meal glucose target is 5-10 mmol/L.
