Diabetes insipidus (DI) and diabetes mellitus (DM) are two medical conditions which are often confused as meaning the same thing. However, you should not mistake DI for DM which occurs when the body does not produce enough insulin or becomes resistant to insulin. DI is associated with excessive urination and thirst. Hence, when you consider DI vs DM, you should know that they are not related in any way, though they may share the same symptoms such as excessive urination and excessive thirst. DM is a common condition compared to DI, which is rare. This could be attributed to the fact that DM is more prevalent compared to DI. That means there is a higher number of people diagnosed with DM compared to those diagnosed with DI. Another reason would be that DM is a serious medical condition which requires adopting a healthy lifestyle, such as exercise and diet, and insulin therapy. Any changes in these factors could be fatal in the long or short term. However, DI is not considered as serious a medical condition and can be managed by drinking enough fluids every day.

What is Diabetes Insipidus ?

Diabetes insipidus is a rare medical condition characterized by high passage of urine due to kidney problems. This condition usually occurs when there is an imbalance of fluids in the body as a result of the kidney failing to regulate body fluids properly. This results in excessive thirst, even after taking water, and excessive urination (polyuria). Because of the high passage of urine, patients with DI may become dehydrated if they do not drink enough water to make up for the lost fluids. When functioning properly, your kidneys will remove excess water from your blood. This water waste will be stored in the bladder in the form urine which will be excreted from your body as urine. In case the fluid regulation system is functioning normally, the kidney will produce less fluids to conserve fluids lost through sweating or diarrhea. Your body regulates fluids by balancing your intake of fluids and excreting excess fluids. The rate of fluid intake is controlled by thirst, while the excretion of fluids is regulated by a hormone known as an antidiuretic hormone (ADH), which is called vasopressin. People who have mild DI can control the condition by drinking enough water every day.

What is Diabetes Mellitus?

Diabetes mellitus is a common condition which is characterized by high levels of blood sugar in the body. This may be as a result of lack of enough insulin or the body becoming resistant to it. There are two common forms of DM, type 1 diabetes and type 2 diabetes. Type 1 diabetes is a chronic condition which occurs when the immune system mistakenly attacks and destroys the beta cells in the pancreas, preventing insulin production. As a result, people with type 1 diabetes require insulin therapy so that they can survive. On the other hand, type 2 diabetes refers to a condition where the body does not produce enough insulin or use it properly. Insulin is a natural hormone produced by the pancreas, which helps to regulate blood sugar levels. Without insulin, people with diabetes experience high blood sugar levels that can lead to health complications or even death if not treated.

What is the Difference Between Diabetes Insipidus vs Diabetes Mellitus?

When understanding the differences of diabetes insipidus vs diabetes mellitus, you have to understand that although they sound the same, the two medical conditions are different. DI is a rare disorder characterized by excessive urination whereas DM is a common condition which is characterized by high blood sugar levels. DM is a pancreas disorder which results in little or no production of insulin. When we eat carbohydrate foods, glucose will be absorbed into the bloodstream. Insulin will work by transporting glucose to the body tissue where it will be stored or used for energy. Glucose is a form of sugar which is one of the main sources of energy. Without insulin, glucose cannot enter the body’s cells and be used as energy, hence they stay in the bloodstream. This will lead to a build up of glucose in the blood, which results in high blood sugar levels. On the other hand, DI is a hypothalamic disorder.

People with DI have a normal blood sugar and insulin levels, but their kidneys cannot properly regulate body fluids. Hence, people with DI will pass high volumes of fluids in the form of urine which is colorless and odorless. Whereas DM is caused by lack of insulin being produced in the body, DI is a result of deficiency in vasopressin. The antidiuretic hormone is made in the hypothalamus, which is a small gland in the brain, and it acts by directing your kidneys to produce less urine. When you start to become dehydrated, the ADH hormone will be released into the blood. The antidiuretic hormone works by stimulating the kidney to release fluids back into the bloodstream instead of excreting it as urine. Although both diabetes insipidus and diabetes mellitus share some of the same symptoms, especially excessive urination, they are very different. The urine output in people with diabetes insipiuds is usually a lot more compared to those with DM. Also, the urine excreted by people with DM is usually of normal concentration, whereas in DI, the urine is very diluted.

Disclaimer: Please note that the contents of this community article are strictly for informational purposes and should not be considered as medical advice. This article, and other community articles, are not written or reviewed for medical validity by Canadian Insulin or its staff. All views and opinions expressed by the contributing authors are not endorsed by Canadian Insulin. Always consult a medical professional for medical advice, diagnosis, and treatment.