Photo of an older couple and a doctor (Alexander Raths / iStock / Thinkstock)

Type 2 diabetes (diabetes mellitus) is a metabolic disease that causes sugar to build up in the blood stream. The severity of diabetes can vary quite a bit: Some people only have to make minor changes to their lifestyle after they are diagnosed. Just losing a little weight and getting a bit more exercise may be enough for them to manage their diabetes. Other people who have type 2 diabetes need long-term treatment that involves taking tablets or insulin. It is then especially important for them to have a good understanding of their disease and know what they can do to stay healthy.

There are two main types of diabetes. Type 1 diabetes usually develops in childhood or teenage years. This disease is a result of damage to the pancreas that leaves it producing either very little insulin or none at all.

Things are different in type 2 diabetes, where insulin is made by the pancreas but the body’s cells gradually lose the ability to absorb and use the insulin. In the past, type 2 diabetes was often referred to as “adult-onset” diabetes because it is commonly diagnosed later in life. Type 2 diabetes is much more common than type 1 diabetes. About 90% of people who have diabetes have type 2 diabetes.


If type 2 diabetes goes untreated, blood sugar levels stay high all the time. This isn't always noticeable at first. Type 2 diabetes can develop gradually over several years without any noticeable symptoms. Blood sugar levels that are always too high may cause the following symptoms, though:

  • Extreme thirst
  • Frequent urination
  • Tiredness and listlessness
  • Nausea
  • Dizziness

If someone has extremely high blood sugar levels, they may feel confused and drowsy or even lose consciousness (diabetic coma).

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Our metabolism converts food into energy for our bodies to use. One of the things needed for this process is insulin.

Insulin is a hormone, which is a chemical that the body uses to send messages. It is made by the pancreas. After you eat something, the sugar levels in your blood rise and insulin is released into the bloodstream. It then makes the cells in your body absorb sugar from the blood – for instance in the liver and in muscle tissue. If this process doesn't work properly, the sugar (glucose) in our blood can't be used in the usual way. This causes blood sugar levels to rise. The medical term for blood sugar levels that are too high is hyperglycemia.

In people who have type 2 diabetes, the pancreas actually produces enough insulin, but it no longer has an effect on the body's tissues and cells. This is what doctors refer to as “insulin resistance.” The pancreas can compensate for this for a while by producing more insulin. But at some point it can no longer keep up, and then blood sugar levels start to rise.

Risk factors

Various factors can increase the likelihood of developing type 2 diabetes:

  • Being overweight and not getting enough physical exercise
  • Smoking
  • A low-fiber, high-fat and sugary diet
  • Certain medications that affect the body’s sugar metabolism
  • Genetic factors: Type 2 diabetes is more common in some families


People who have type 2 diabetes are also at greater risk of developing cardiovascular conditions such as a heart attack, stroke or problems with the circulation in their legs and feet (peripheral artery disease, PAD). These are among the macrovascular complications of diabetes. “Macrovascular” means that these complications affect the larger blood vessels. The risk of developing them is especially high in people who also have high blood pressure.

If there is too much sugar in the blood over many years, the smaller blood vessels supplying the eyes, nerves and kidneys can become damaged too. These are known as the microvascular complications of diabetes. “Microvascular” means that the smaller blood vessels are affected. The medical names for these kinds of complications are retinopathy (damage to the retina of the eye), neuropathy (nerve damage), and nephropathy (kidney damage). The later someone develops type 2 diabetes, the less likely it is that they will develop these kinds of problems.

A typical example of the nerve damage and circulation problems that can result from diabetes is called "diabetic foot." This occurs when the nerve damage is so severe that pain in the foot can hardly be felt at all. Then things like blisters and bruises can easily lead to wounds that don't heal well. That is because poor blood circulation in the legs and feet affects the wound healing process, slowing it down. The nerve damage may also cause some muscles in the foot to shrink, deforming the foot.

Damage to the retina isn’t noticeable at first. But vision gets worse over time – sometimes even leading to blindness. Your eyesight is particularly at risk if the small blood vessels in the region of sharpest vision, the macula, are damaged. Fluid may build up there and lead to macular edema. In Germany, some eye doctors offer optical coherence tomography (OCT) to diagnose and treat macular edema as an individual health care service (in German: individuelle Gesundheitsleistung, or IGeL for short). Because optical coherence tomography hasn’t been proven to help, it’s not covered by the statutory health insurers.

Research summaries


Because type 2 diabetes develops so gradually, people often only have minor symptoms or no symptoms at all to start off with. High blood sugar levels in blood or urine are often first detected during a routine check-up. If your doctor thinks you might have type 2 diabetes, he or she will first ask about any symptoms and other conditions that you may have. You will then also have a physical examination and your blood sugar levels will be measured. To check your blood sugar levels before your first meal and over the course of a day, several blood samples are taken and then analyzed in a laboratory. The HbA1c value is also measured: This value is a measure of the average blood sugar levels over the last two to three months.

If blood sugar levels are high enough to be causing typical diabetes symptoms, sugar can usually be detected in urine as well. You can measure the level of sugar in your urine with easy-to-use test strips. These are available from pharmacies and doctor's practices in Germany and many other countries.

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There’s a lot of advice out there about how to prevent type 2 diabetes. It mainly concerns lifestyle factors such as eating a balanced diet, getting enough exercise, and keeping your weight down as a result.

In people who are at a greater risk of developing diabetes, changing their diet and getting more exercise can actually help delay the onset of diabetes for a number of years. But it is not clear whether eating the "right" foods and getting more physical activity can help you prevent diabetes completely, as some experts hope.

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A number of factors influence which treatment approach for type 2 diabetes is most suitable: They include age, general physical condition, other health problems, life circumstances and personal goals.

Sometimes just changing your lifestyle can have a positive effect: Losing weight and getting more exercise can make insulin more effective and lower blood sugar levels. Quitting smoking helps to reduce the risk of cardiovascular disease. Making these kinds of changes is sometimes enough to manage the condition and associated risks.

If very overweight (obese) people find it hard to lose weight, surgical approaches such as stomach stapling may be an option.

Some people depend on medication to regulate their blood sugar levels. The medication options include taking tablets, injecting insulin or medication called incretin mimetics (hormone-like substances that are designed to increase the body's insulin production). It's also possible to combine tablets and injections. The most common medications used to treat type 2 diabetes (antidiabetic drugs) are metformin and sulfonylureas. Newer antidiabetic drugs are also available – but there are still many unanswered questions about their effects.

Depending on what other symptoms and illnesses a person has, different kinds of medication can be used to lower particular risks. For example, many people who have type 2 diabetes also have high blood pressure.

The main medications that can lower the risk of cardiovascular disease

  • lower blood pressure (antihypertensives),
  • prevent blood clotting (ASA, the drug in medications like Aspirin), or
  • reduce cholesterol levels (statins).

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Everyday life

There are some things that people who have type 2 diabetes can do to get by without medication. The most important thing is to lose at least a little weight – even though that may be difficult to achieve in practice. Even just a little more physical activity can have a positive effect, for example getting into the habit of walking more often.

If that is not enough, medication is an option, but that then has to be taken regularly over a long period of time. It can be difficult to get used to the idea of taking medication for the rest of your life – especially if you don’t feel ill and don’t notice any immediate benefits. Managing type 2 diabetes treatment can be a real challenge, particularly at first. But knowing all about diabetes can make dealing with the condition a normal part of your daily routine and help you maintain a high quality of life.

Further information

No matter what type of treatment you end up choosing, the key to managing diabetes is understanding the disease and knowing what you can do to help protect your own health. It is also important to have the support of your doctor and other specialists, including diabetes consultants, diet consultants, and foot specialists (podiatrists).

In Germany there is also a wide range of different services for individual advice and support if you are ill. Many of these offers vary greatly, depending on where they are based, and they are not always easy to find. A list of points of contact can help you to locate and make use of local offers.

Taking part in a “disease management program” (DMP) is another option. Here diabetes specialists offer patient education, advice and comprehensive medical care.