Diabetes mellitus is a metabolic disease that causes high blood sugar. Your body either doesn’t make enough insulin or can’t effectively use the insulin it makes.

The hormone insulin moves sugar from the blood into your cells to be stored or used for energy. If this malfunctions, you may have diabetes.

Untreated high blood sugar from diabetes can damage your nerves, eyes, kidneys, and other organs. But educating yourself about diabetes and taking steps to prevent or manage it can help you protect your health.

Types of diabetes

There are a few different types of diabetes:

Type 1: Type 1 diabetes is an autoimmune disease. The immune system attacks and destroys cells in the pancreas, where insulin is made. It’s unclear what causes this attack.

Type 2: Type 2 diabetes occurs when your body becomes resistant to insulin, and sugar builds up in your blood. It’s the most common type—about 90% to 95% of people living with diabetes have type 2.

Type 1.5: Type 1.5 diabetes is also known as latent autoimmune diabetes in adults (LADA). It occurs during adulthood and sets in gradually like type 2 diabetes. LADA is an autoimmune disease that cannot be treated by diet or lifestyle.

Gestational: Gestational diabetes is high blood sugar during pregnancy. Insulin-blocking hormones produced by the placenta cause this type of diabetes.

A rare condition called diabetes insipidus is not related to diabetes mellitus, although it has a similar name. It’s a different condition in which your kidneys remove too much fluid from your body.

Prediabetes

Prediabetes is the term that’s used when your blood sugar is higher than expected, but it’s not high enough for a diagnosis of type 2 diabetes. It occurs when the cells in your body don’t respond to insulin the way they should. This can lead to type 2 diabetes down the road

Symptoms of diabetes

Diabetes symptoms are caused by rising blood sugar.

General symptoms

The symptoms of type 1, type 2, and type 1.5 (LADA) are the same, but they occur in a shorter period than types 2 and 1.5. In type 2, the onset tends to be slower. Tingling nerves and slow-healing sores are more common in type 2.

Left untreated, type 1, in particular, can lead to diabetic ketoacidosis. This is when there is a dangerous level of ketones in the body. It’s less common in other types of diabetes, but still possible.

The general symptoms of diabetes include:

• increased hunger
• increased thirst
• weight loss
• frequent urination
• blurry vision
• extreme fatigue
• sores that don’t heal

Symptoms in men

In addition to the general symptoms of diabetes, men with diabetes may have:

• a decreased sex drive
• erectile dysfunction
• poor muscle strength

Symptoms in women

Women with diabetes can have symptoms such as:

• vaginal dryness
• urinary tract infections
• yeast infections
• dry, itchy skin

Gestational diabetes

Most people who develop gestational diabetes don’t have any symptoms. Healthcare professionals often detect the condition during a routine blood sugar test or oral glucose tolerance test, which is usually performed between the 24th and 28th weeks of pregnancy.

In rare cases, a person with gestational diabetes will also experience increased thirst or urination.

Causes of diabetes

Different causes are associated with each type of diabetes.

Type 1 diabetes

Doctors don’t know exactly what causes type 1 diabetes. For some reason, the immune system mistakenly attacks and destroys insulin-producing beta cells in the pancreas.

Genes may play a role in some people. It’s also possible that a virus sets off an immune system attack.

Type 2 diabetes

Type 2 diabetes stems from a combination of genetics and lifestyle factors. Having overweight or obesity increases your risk, too. Carrying extra weight, especially in your belly, makes your cells more resistant to the effects of insulin on your blood sugar.

This condition runs in families. Family members share genes that make them more likely to get type 2 diabetes and to be overweight.

Type 1.5 diabetes

Type 1.5 is an autoimmune condition that occurs when the pancreas is attacked by your own antibodies. as in type 1. It may be genetic, but more research is needed.

Diabetes complications

High blood sugar damages organs and tissues throughout your body. The higher your blood sugar is and the longer you live with it, the greater your risk for complications.

Complications associated with diabetes include:

• heart disease, heart attack, and stroke
• neuropathy
• nephropathy
• retinopathy and vision loss
• hearing loss
• foot damage, such as infections and sores that don’t heal
• skin conditions, such as bacterial and fungal infections
• depression
• dementia

Gestational diabetes

• Unmanaged gestational diabetes can lead to problems that affect both the mother and baby. Complications affecting the baby can include:
• premature birth
• higher-than-typical weight at birth
• increased risk for type 2 diabetes later in life
• low blood sugar
• jaundice
• stillbirth

A pregnant person with gestational diabetes can develop complications such as high blood pressure (preeclampsia) or type 2 diabetes. You may also require cesarean delivery, commonly referred to as a C-section.

The risk of gestational diabetes in future pregnancies also increases.