Differentiation of polyphagia and polyuria from diabetes

Polyuria and diabetes.

In hospital clinical work, patients with increased urine output and drinking habits (polyphagia and polyuria) are often encountered. It is important to carefully analyze the condition and distinguish it from diabetes. Below are some cases that can also cause polyphagia and polyuria.

1. Psychogenic polyuria, the etiology of this disease is not completely clear, and there are many mental tension factors, which may be related to the nervous disorder regulating urinary and drinking water. The patient only has polyuria because he drinks too much, and because he urinates too much, it will in turn stimulate the hypothalamic thirst center, ingest a large amount of water, and form a vicious cycle. It is more appropriate to call this disease psychogenic polydipsia. Generally, after the removal of mental factors, the condition usually relieves itself.
2. Diabetes insipidus: A disease caused by insufficient or absent antidiuretic hormone (ADH). In this disease, the hypothalamus or posterior pituitary gland dysfunctionally synthesizes or stores ADH, resulting in decreased reabsorption of water by the kidney tubules and collecting ducts. This leads to a large amount of water being excreted in the urine and subsequently causes thirst and increased water intake. Some patients drink more than 10,000 ml of water per day.
3. Chronic renal insufficiency: Many chronic nephritis and pyelonephritis can also cause increased urine output, especially nocturnal polyuria.
4. Other factors: Climate factors, such as excessive sweating in hot weather and reduced sweat evaporation in cold weather, can also cause relative polyuria. Elderly men often have prostate hyperplasia and other conditions, which can lead to increased frequency of urination, but the total daily urine volume is not necessarily high.

In conclusion, simply having increased urine output and drinking habits does not necessarily mean diabetes. Further tests for blood sugar and urine sugar should be conducted to make a definitive diagnosis.

polyphagia and diabetes

Many diseases can cause excessive eating, which needs to be distinguished from diabetic gluttony.

1. Hyperthyroidism (Graves’ disease): When the thyroid hormone secretion increases in hyperthyroidism, the metabolism of carbohydrates, proteins, and fats accelerates, resulting in excessive energy consumption. On the other hand, increased intestinal absorption and peristalsis lead to a feeling of hunger. These factors can all cause excessive eating. However, hyperthyroidism has its characteristic manifestations, which are generally easy to distinguish.
2. Insulinoma: Also known as islet cell tumors, more than 90% are benign tumors that can secrete large amounts of insulin or insulin-like substances, causing blood sugar to decrease, and the glucose concentration difference between arterial and venous blood to shrink. The feeding center is stimulated, leading to hunger and excessive eating. Over time, patients develop obesity. Due to the frequent occurrence of hypoglycemia, patients often have neuropsychiatric symptoms such as hunger, palpitations, cold sweat, dizziness, memory loss, slow response, etc., which are easily distinguishable from diabetes.
3. Cushing’s syndrome: Cushing’s syndrome can cause increased appetite due to increased cortisol levels. The mechanism is unclear, and there are several explanations:
   ① Cortisol can promote the increase and growth of gastric wall cells, increase gastric acid and pepsin secretion, and reflexively stimulate the feeding center.
   ② Corticosteroids promote the breakdown of proteins and fats, increasing the levels of free fatty acids and amino acids in the blood, which may have a stimulating effect on the feeding center.
   ③ Cortisol can promote gluconeogenesis and inhibit glucose utilization, leading to steroid diabetes in severe cases and causing excessive eating. Cushing’s syndrome has typical symptoms and appearance, making it easy to distinguish.
4. Pheochromocytoma: Excessive eating is not a prominent feature of this disease. Some patients may experience increased appetite, possibly related to the stimulation of the feeding center by increased levels of catecholamine hormones. The prominent feature of this disease is hypertension.
5. Excessive growth hormone secretion, such as gigantism and acromegaly, can cause excessive eating. Combined with their related clinical manifestations, it is not difficult to distinguish from diabetes. However, it should be noted that these diseases can also secondary to diabetes.
6. Hypothalamic syndrome: Lesions or dysfunction of the hypothalamus can excessively stimulate the feeding center, causing excessive eating and obesity.