The sugars we ingest daily through our foods are transformed by our bodies, through a highly complex metabolic process that involves the hormone insulin, into glucose. This monosaccharide, also known as dextrose, is then diffused into the bloodstream where it travels to the cells of diverse types of tissues providing the necessary energy they require to function correctly. One of the clearest examples of this vital process is seen in the various muscle tissues of the body, which must be fueled by glucose in order to perform any movement.
The levels of glucose present in the bloodstream are clinically known as Glycemia and typically fluctuate throughout the course of a typical day. These varying concentrations can range anywhere from 70 to 145 milligrams per deciliter of blood. Glycemic levels generally are lower in the morning, rise after eating, and subsequently, fall back down to normal levels approximately two hours after each meal. For this reason, blood glucose levels are measured early in the morning before breaking fast, at which time results that fall in the range of 70 to 100 mg/dl are considered optimal.
Alterations of blood glucose
Sometimes, when metabolic function breaks down, Insulin action is affected sufficiently to the point where the various cells and tissues of the body stop assimilating glucose efficiently and it begins to accumulate in the blood. When fasting blood glucose levels reach the range between 100 and 125 mg/dl and post-meal levels exceed 140 mg/dl, the patient is said to have Hyperglycemia or high blood sugar.
Glycemic values that fall within this range represent what is known as a prediabetic state, in which Type 2 Diabetes, while not yet manifested, enters a “prelude” stage. In these cases, there is still time for lifestyle modification, such as weight loss, adopting a balanced diet, exercising daily, which may be enough to revert Glycemia to a healthy range and delay, or outright prevent the development of full-blown diabetes.
However, while there remains an excess of glucose in the bloodstream a particular set of symptoms will appear, some of which range from mildly annoying to potentially life-threatening. Let us take a closer look at the most clinically significant symptoms that are generally associated with elevated levels of blood sugar.
High blood sugar symptoms (Hyperglycemia symptoms)
1. Polyphagia
Polyphagia, or an excessive sensation of hunger, is the first of three classic signs of Hyperglycemia and is likely based on the development of an imbalance in the hypothalamic centers of satiety and feeding. In the case of patients with elevated levels of blood glucose, polyphagia arises from a reduction in the utilization of available carbohydrates which generates a state of hydrocarbon starvation and, through a mechanism that is not fully understood, the hypothalamic centers of the brain are affected. The result is a dramatic increase in the desire to eat and ingest solids.
In this sense, it is of interest to remember that there are insulin receptors in the ventromedial zone of the hypothalamus and that the presence of said hormone would be necessary for glucose to enter the cells that regulate the sensation of satiety. Curiously enough, once insulin resistance becomes severe, appetite is actually suppressed in a large subset of patients.
2. Polydipsia
Polydipsia, or excessive thirst, is the second of the three classic signs of elevated levels of blood glucose. The balance of the metabolism of water in the body is the result of a delicate interplay constituted by the sensation of thirst, the production of metabolic water, the ingestion of exogenous water contained in food and drink, and the expulsion of the same through the skin, the respiratory system, the gastrointestinal tract, and urinary system. Thirst is the subjective sensation that leads to the intake of water. The physiological factors that determine the appearance of an increased sensation of thirst are linked to an increase in the osmolarity of extracellular fluid and this is determined by an excess of salts, a deficit of fluids, and a decrease in the circulating vascular volume. The conscious desire to drink appears when plasma osmolarity reaches 295 mOsm/kg, which is continuously achieved and surpassed when blood glucose is too high. Factors such as sodium consumption normally influence the appearance of thirst, and a basic component of its stimulation is dryness of the mucous membranes of the mouth and pharynx, which is also commonly experienced by patients with elevated blood sugar.
3. Polyuria
Any alteration to the complex mechanisms that regulate urinary concentration can lead to the clinical development of polyuria. Not to be confused with polyurea, polyuria is the excessive or abnormal production of urine and is the last of the three classic symptoms of Hyperglycemia. In the case of Hyperglycemia, polyuria presents when the patient experiences insufficient secretion of ADH, or Antidiuretic Hormone, which limits the maximum urinary concentration.
4. Blurred Vision
Hyperglycemia can damage the small blood vessels of the eye. Additionally, Hyperglycemia significantly increases the risk of developing glaucoma, cataracts, and other ocular disorders. When sufficient damage has been done to the blood vessels near the retina, a severe condition known as Diabetic Retinopathy can develop. Diabetic Retinopathy is considered the leading cause of decreased vision or blindness in Americans aged 20 to 70 years. People with type 1 or type 2 diabetes are at significant risk of developing this debilitating condition.
5. Fatigue
Fatigue is one of the most frequent symptoms seen in medical practice. It is usually accompanied by other symptoms and is a significant component of a wide variety of syndromes or clinical conditions. Fatigue, also known as lassitude, can be considered a normal sensation when it occurs after a day of work or intense physical effort. However, when fatigue can no longer be considered a normal response to the day’s demands and becomes a chronic condition, and cannot be easily attributed to known triggers, it is considered an abnormal state and some underlying pathological reason must be considered.
Fatigue can be caused by infections, metabolic disorders, renal failure, hepatic failure, pulmonary distress, cardiovascular disease, neurovascular disease, and blood disorders. In the case of Hyperglycemia, most experts agree that the feeling of fatigue arises from the development of acidosis at the muscle fiber level. Endocrine alterations, which are known to generate states of hypermetabolism with increased energy consumption, electrolyte loss, exaggerated protein catabolism, and nutrient deficiency can also contribute to the appearance of chronic fatigue.
6. Weight Loss
The loss of corporal weight is a clinical manifestation of numerous pathological processes, including Hyperglycemia. A loss of weight greater than 10 kilograms is generally associated with marked changes in physical appearance and can lead to marginal manifestations of malnutrition. Cachexia is defined as a weight decrease greater than 40% below normal with regards to sex, age, and height. Secondary weight loss may be accompanied by asthenia and fatigability, arterial hypotension, insomnia or drowsiness, depression, menstrual alterations in women, reduction of subcutaneous cellular tissue and muscular atrophy. The overall result of these manifestations is typically followed by hypoproteinemia, which is a reduction in blood protein levels, in addition to a dramatic depression of the immune apparatus.
In patients with Hyperglycemia, weight loss may be due in part to the increased urination described above. It can also occur mainly in insulin-dependent diabetes, due to caloric loss through glucosuria and insulin deficiency, which results in less synthesis and higher catabolism of fats and proteins. Interestingly, in patients with hyperglycemia weight loss is observed in spite of the presence of polyphagia.
7. Poor Healing
Hyperglycemia causes the healing of wounds to be slower and more difficult than normal. Patients with elevated levels of blood sugar not only show altered healing in acute wounds and slow tissue closure, but they are also more sensitive to chronic wounds, such as ulcerative lesions in the lower limbs, which can lead to unnecessary amputations due to infections. This circumstance is caused by an inhibited or deteriorated inflammatory reaction and by a diminished capacity to release growth factors and cytokines, which provide cells with various beneficial functions. Additionally, a common complication of patients with severe Hyperglycemia is the obstruction of the blood vessels in the lower extremities, which further reduces the capacity of the circulatory system to transport blood and repair cells throughout the body. Subsequently, the phenomenon of epithelialization, which is the closure of the skin from the periphery to the center of the wound, is hindered by insufficiency of growth factors. All these factors combined cause significantly slower healing, and an increased risk of infection.
8. Cardiac Arrhythmia
Hyperglycemia has been known to affect the nerves that permeate the heart and cause alterations in the cardiac rhythm that are also known as arrhythmia. Arrhythmia is considered by most experts as one of the most clinically significant cardiovascular risk factors, because it is heavily involved in the development of atherosclerosis, ischemic heart disease and its many clinical manifestations such as angina, infarction, etc. Patients with Hyperglycemia, which are at significantly increased risk of developing diabetes, also regularly experience a decreasing capacity for myocardial contraction, as well as a decreased sensitivity to pain, so it is not uncommon for these patients to experience silent infarcts or asymptomatic heart attacks.
» Conclusion
The human endocrine system regulates the amount of sugar that is stored and used for the energy necessary for the functioning of the cells. The sugars that are consumed in our daily diets are used up or stored as a metabolic fuel, but certain conditions and disorders can cause a significant decrease in the body’s ability to process and store glucose as energy, which can result in an abnormal accumulation in the bloodstream. Hyperglycemia is simply an excess of blood sugar or glucose.
Levels of blood sugar are considered normal when they fall in the range of 70 to 145 mg/dl. Normal values may vary depending on the laboratory. Levels above these may indicate Hyperglycemia.
Hyperglycemia may be caused by a variety of clinically significant reasons, not the least of which is a diabetic disease. If you are overweight, if there is a family history of diabetes, or belong to specific ethnic groups such as African American, Hispanic or American Indian, you are at an increased risk of developing some form of diabetes.
Perhaps one of the single most influential and easily modifiable risk factors in the development of Hyperglycemia is physical activity levels. Regular exercise dramatically reduces the associated risks by diminishing blood sugars and promoting the circulation of blood. Diet also plays an important role in the prevention of this condition.
It is important to note that patients with diagnosed kidney or liver disease may experience elevated levels of blood sugar. It is also normal for glycemic values to increase temporarily during periods of viral or bacterial infections. Pregnant women are also susceptible to developing temporary gestational diabetes, which is characterized by increased levels of blood sugar, which typically normalize after birth.
Prolonged Hyperglycemia has the potential to cause vision loss, metabolic imbalances, and even kidney failure. Additionally, there are many long-term complications due to prolonged Hyperglycemia, such as cardiac problems and degeneration of the circulatory system. In cases of severe Hyperglycemia, blood sugar levels can rise to the point of causing seizures and coma.
Thankfully, Hyperglycemia can be easily detected with a simple and painless laboratory test and, if done so early enough, it can be easily treated with regular exercise and a moderated diet.
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