Low blood glucose (below 70 mg/dL or 3.9mmol/L) or hypoglycaemia can manifest in many confusing ways, like epileptic fit, stroke, or coma. Common early symptoms include trembling (tremor), sweating, fatigue, hunger, headache, dizziness, drowsiness, and light-headedness (feeling faint).
Lower blood sugar presents with fast or irregular heartbeat, confusion, irritability, blurred vision, slurred speech, and difficulty concentrating. In severe cases (below 50mg/ dL or 2.8mmol/L), epileptic fit like seizures, stroke like weakness or paralysis of part or half of the body or loss of consciousness can occur as the brain is heavily dependent on a continuous supply of glucose, as it cannot store glucose, its primary energy source.
Some individuals may not experience signs of low blood sugar; hence, it may not be recognized and treated, leading to grave consequences. A normal fasting glucose level is 70 to 99 mg/ dL (3.9 to 5.5mmol/L). Levels of 100 to 125mg/ dL (5.6 to 6.9mmol/L) are considered prediabetes, and levels of 126mg/dL (7mmol/L) (Hyperglycaemia) or higher on two separate tests indicate diabetes. People with prediabetes have up to a 50% chance of developing Type 2 (lateonset) diabetes over 5 to 10 years, but can reverse to a normal state by changes in lifestyle, eating habits, and diet control. Blood glucose levels are 200 mg/ dL (11.1mmol/L) or higher in Type 1 (early onset) diabetes.
HYPOGLYCAEMIA: Low blood sugar is often associated with too much diabetes medication or too little or untimely food intake. It can also occur in nondiabetic individuals due to prolonged fasting, certain medications, excessive insulin producing tumour (Insulinoma), deficiency of insulin opposing hormones like steroids (Addison’s disease) and growth hormone; and inherited inability to breakdown stored fat to glycerol (which is converted to glucose in liver), and fatty acids (which is oxidised or converted in liver to ketone bodies), to release energy.
Fatty acids and ketone bodies are glucose substitutes for energy release. It is crucial to correct low blood sugar promptly by consuming fruit juice, sugar, or glucose tablets. Severe symptoms, such as loss of consciousness or seizures, require immediate medical attention.
INSULINOMA: It is a rare, usually non-cancerous, neuroendocrine tumour in the pancreas that produces too much insulin, leading to low blood sugar, especially when fasting. Early symptoms are dizziness, lightheadedness, weakness, sweating, hunger, and confusion, the same as those of mild hypoglycaemia mentioned above. Later, these patients have episodes of epilepsy, like fits, and are often treated with antiepileptic drugs.
This author, one of the few surgeons worldwide with experience in the removal of Insulinoma without collateral damage, by laparoscopic enucleation, has seen almost all patients coming late, after undergoing treatment for epilepsy. The most important differentiating point is that these fits occur after overnight or prolonged fasting, unlike fasting-unrelated epileptic fits. Surgical removal leads to a full and permanent recovery, except if the Insulinoma is cancerous or due to a genetic cause.
HYPERGLYCAEMIA: High blood sugar is usually due to diabetes, and infrequently due to low insulin levels, due to damage to its source (pancreatitis), or raised ‘anti-insulin’ hormones like steroids with steroid, certain medications, and steroid producing tumours (Cushing syndrome), stress hormones (adrenaline and noradrenaline) under severe stress from surgery or trauma, and in stress hormones producing tumour (Pheochromocytoma), glucagon hormone producing tumour (Glucagonoma), growth hormone producing pituitary tumour, and thyroid hormone in hyperthyroidism.
IMPORTANCE OF STABLE GLUCOSE LEVELS: Unstable glucose levels can destabilise your life. An HbA1c test reveals average blood sugar over a few months, not the variations. Diabetes can manifest with increased thirst and frequent urination, unexplained weight loss, fatigue, increased hunger, blurred vision, numbness or tingling in hands and feet, and slow-healing sores.
Persistent or repeated high blood sugar, as seen in poorly controlled diabetes, damages blood vessels and nerves, leading to serious complications like infections, limb loss, heart disease, kidney disease, and vision loss. Stable glucose levels reduce hunger cravings, improve energy levels, mood, well-being, focus, cognitive function, and sleep quality. Regular meals, appropriate medication, and monitoring blood sugar levels can help prevent hypoglycaemia. Glucose levels can be stabilised with regular monitoring, a diet of complex carbohydrates, lean protein, and healthy fats, avoiding processed foods and sugary drinks, regular exercise or physical activity, stress management, and adherence to the diabetes treatment plan.
CONTINUOUS GLUCOSE MONITORING (CGM): These devices help manage diabetes better than intermittent checks. A sensor inserted under the skin with an applicator, and held in place with an adhesive patch, continuously measures glucose levels in the interstitial fluid. A transmitter sends results to a wearable device or cell phone so that changes in glucose level can be tracked in real time. It helps you to realise which food and quantities causes your glucose levels to spike and when, thus you can modify your food choices and timing. It also helps your doctor adjust, versatile oral medications and insulins, now available. For rapid control of very high, unstable glucose levels, insulin pumps are used with CGMs. CGMs may be used in prediabetes, obesity, certain glycogen storage diseases, and in Insulinoma.
Awareness of symptoms of low and high glucose levels, their prevention, and the need for adequate management is essential to prevent serious complications and loss of life.
Dr. P.S.Venkatesh Rao is a Consultant Endocrine, Breast & Laparoscopic Surgeon, Bengaluru.
