A person shows symptoms of high blood sugar, frequent urination and thirst. Which hormone is likely deficient? (NEET 2020)
Correct answer: D — Insulin
These symptoms (high blood sugar, frequent urination, thirst) indicate diabetes mellitus caused by insulin deficiency. Insulin normally promotes glucose uptake by cells. Without adequate insulin, glucose accumulates in blood (hyperglycemia), excess glucose is excreted in urine causing frequent urination, and this leads to dehydration causing excessive thirst. Glucagon raises blood sugar, so its deficiency wouldn't cause these symptoms.
Prolonged hyperglycemia leads to a complex disorder called diabetes mellitus which is associated with loss of glucose through urine and formation of harmful compounds known as ketone bodies. Diabetic patients are successfully treated with insulin therapy.
Diabetes mellitus is a metabolic disorder where prolonged hyperglycemia (high blood sugar) causes glucose to be lost through urine instead of being reabsorbed. This occurs when blood glucose exceeds the renal threshold (typically >180 mg/dL), and the kidneys cannot reabsorb all the filtered glucose. Students often confuse glycosuria (glucose in urine) with kidney damage—it's actually a sign of uncontrolled blood glucose. Additionally, understand that diabetic patients cannot properly use glucose due to insulin deficiency or resistance, leading to ketone body formation as an alternative fuel source. Remember: insulin therapy restores glucose homeostasis and prevents complications like ketoacidosis.
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