Alternation of blood glucose level:

When the blood glucose level is within the normal limits, it is called as normoglycemia, if it is high then it is called as hyperglycemia and if it is low it is called as hypoglycemia.

Hyperglycemia is seen in the following cases:

1. Diabetes mellitus:

It can be of two types Type I and type II.

DM type I: it is due to the deficiency of the insulin in the blood and is also called as insulin dependent diabetes. Because of the deficiency of insulin the tissues cannot uptake the glucose from blood and hyperglycemia occurs.

DM type II: it is due to the resistance of insulin ie insulin cannot work properly. It is also referred as insulin resistant diabetes. Here, the circulating insulin can be normal but there is less sensitivity if insulin to the glucose and hyperglycemia occurs. This is mainly found in dog and cat.

2. Pancreatitis: In this condition hyperglycemia occurs due to inhibition of production of insulin by the pancreas. Viral infection and autoimmune disease is the main cause of pancreatitis.

3. Hyperadrenocoticism: when there is high production of Glucocorticoids, it leads to increase in blood sugar by increasing gluconeogenesis.

4. Increases secretion of steroid hormones may also lead to hyperglycemia .

5. Hyperthyroidism: thyroxine helps to increase the blood sugar so during hyperthyroidism hyperglycemia can occur.

6. Some other cause can be amyloidosis, heavy carbohydrate meal etc.

Hypoglycemia can be seen in the following cases:

1. Hyperinsulinism: over production of insulin can lead to hypoglycemia. It is seen in pancreatic tumor. Sometimes over injection of insulin can also lead to hypoglycemia.
2. Glycogen storage disease: some of the glycogen storage disease like Von Gierke’s disease, cori disease can also lead to hypoglycemia.
3. Hypothyroidism, hypoadrenocorticism etc can lead to hypoglycemia due less production of thyroxine and Glucocorticoids.
4. During starvation and malnutrition also hypoglycemia can be seen.