The stroke restricts the blood flow to the brain.

A stroke usually causes drastic changes in the lives of the patient and family members. This condition often occurs abruptly mostly without any prior warning and can suddenly tear an active person away from life and is a painful experience for all those involved. They are suddenly confronted all at once with topics such as disability and care requirements and on top of this social and economic problems.


Stroke. Definition

What is a stroke?

By "stroke" we mean an abrupt ("out of the blue") loss of certain functions of the brain. The usual cause in most cases is a sudden disturbance in blood flow in the brain in which the affected parts are no longer supplied with oxygen and nutrients. The nerve cells in the brain which are however supplied with oxygen carried by blood, can die because of the lack of blood flow. All depending on which parts of the brain are affected, this can result in the loss of important everyday capabilities manifesting as paralysis, loss of sensation, speech or vision. When a stroke occurs both the main cerebral arteries and also the small vessels in the brain can be blocked.


Find all you need to know about a stroke.

The more information you have about what causes strokes and how to prevent them, the greater your chances are, even after a stroke, of staying courageous or even stopping it from ever getting to that stage.


A stroke is the 3rd most common cause of death.

In Germany every year between 160,000 and 250,000 people have a stroke. Around 20 per cent of patients directly affected by a stroke die within four weeks and over 37 per cent within a year. It is the most frequent cause of disability and the third most frequent cause of death after cardiac infarction and cancer. The costs incurred because of strokes are estimated to be around 10,000,000,000 € a year. These figures not only make clear how widespread strokes are, but also how important it is to be well-informed about this affliction. Because many strokes can be avoided through the right actions and precautionary measures.




Stroke. Symptoms

Everyone should recognise the symptoms which indicate a stroke:

  • sudden paralysis of part of the body, an arm or leg or half of the face, unusual sensations in the limbs (tingling or numbness)
  • sudden problems speaking with unclear, indistinct speech, problems understanding what has been said or complete inability to speak
  • sudden visual weakness or blindness in one eye or on one side of the visual field (in a left or right direction)
  • sudden double vision, blurred vision
  • sudden feelings of dizziness with nausea and vomiting, balance and coordination problems
  • sudden unconsciousness, confusion (in time, place or in relation to people)
  • abrupt onset of a very severe headache (like a bolt out of the blue)

Usually those affected experience no pain during a stroke unless it is accompanied by a severe headache. For this reason many strokes, especially mild ones, go unnoticed. Conversely many people frequently fail to recognise a stroke in someone else.


Precursors to a stroke.

In around a third of all strokes there are warning signs, the so-called transitory ischaemic attacks (TIA), a transient disturbance of blood flow in the brain. With such strokes only lasting a short time, the blood clot immediately breaks up again, so that no brain cells die. The above-mentioned neurological deficits occur only for a few minutes and seldom last longer than one or two hours. They may however also last up to 24 hours. Transitory ischaemic attacks leave no lasting damage behind and the symptoms go away completely after a while.


Take the warning signs of a stroke seriously.

Important: These disruptions in blood flow, which herald a stroke, must be taken seriously. Every minute counts. Should you observe the above-mentioned warning signs in other people, bring the patient as quickly as possible to a hospital, because there is a real increased risk of a major stroke occurring, especially in older people and if there are lasting symptoms such as paralysis in one half of the body and difficulties speaking. Immediate medical treatment may possibly prevent a major stroke or at least limit complications and any other consequences.


Stroke. Causes

This is how a stroke develops.

The following different types of stroke are differentiated depending on their cause:

  • Inadequate blood supply to the brain: In approx. 80 per cent of cases there is a blockage in a cerebral blood vessel, caused for instance by a blood clot. This causes inadequate blood circulation (ischaemia). This means that the supply of blood and oxygen is no longer adequate to certain regions of the brain. If the symptoms are transitory in nature then in most cases this is referred to as a transitory ischaemic attack (TIA). Here too rapid medical clarification is needed as there is a real fear that other circulatory problems may occur. Vascular occlusions arise because of the transportation of blood clots (embolisms), or because of localised vascular occlusion in the afferent arteries (arterial thrombosis ). In the case of a microangiopathy, changes in the small arteries in the inner brain cause less damage to the brain tissue
  • Cerebral haemorrhages: In approx. 20 per cent of cases a stroke can also be caused by cerebral haemorrhages. When this happens blood penetrates at high pressure into the surrounding tissue of the brain from burst vessels, which have usually been damaged previously by arterial calcification. The cause is usually high blood pressure or a sudden tear in an artery.
  • Subarachnoid haemorrhages: Two to five per cent of strokes are induced by subarachnoid haemorrhages. When this occurs there is bleeding into the space between the brain and the soft meninges (arachnoidea). This so-called subarachnoid space is normally filled with cerebral fluid.
  • More uncommon causes: These may be inflammation of the vessels, spontaneous injuries or trauma to the vessels disorders of the coagulation system or the formation of clots in the venous sinuses ( sinus venous thrombosis).

Other causes of a stroke: Arteriosclerosis.

Ischaemic attacks can occur because of a blockage in a cerebral blood vessel because of arterial calcification (arteriosclerosis) on the inner walls of the vessel. This makes the vessel even more tightly occluded with severe restriction or even complete interruption of the blood flow to the brain.


Other causes of a stroke: Thromboses.

Vascular occlusion however can also be caused by a thrombosis. This occurs when as a result of arteriosclerosis a vessel wall ruptures. Then through the activation of the body's own blood coagulation system, platelets (thrombocytes) gather at the site of the wound for purposes of agglutination by adhering to one another. This blood clot or platelet plug (thrombus) thus formed increases in size until it completely blocks the vessel.


Other causes of a stroke: Embolisms.

Another cause for arterial occlusion can be an embolism. When this occurs a blood clot breaks free somewhere in the body and is carried to the brain in the blood stream. It can easily penetrate into the small vessels and get lodged there. The most common site for the formation of blood clots is the heart. Dysrhythmias, a fresh cardiac infarction, enlargement of the heart cavities, changes in the heart valves and a congenital hole in the septum of the heart are risk factors for the formation of blood clots. If the blockage in the vessel is not broken up in the first few hours, then the part of the brain supplied by the artery will die irrecoverably. Both the main cerebral arteries, which are approx. 2 - 5 mm thick and also their branches of only 1 mm diameter or less can be affected by an arterial occlusion. A blood clot does not need to be big to block an artery and cause a stroke.


Other causes of a stroke: Cerebral haemorrhage.

Cerebral haemorrhages occur because an artery bursts in the brain. The most frequent cause is continually high blood pressure over a long period of time, which has caused the small arteries in the brain to become stiff and brittle. They can no longer bear the pressure and they burst. Other possible causes are congenital areas of weakness in the vessels and disorders of blood coagulation.


Other causes of a stroke: Haemorrhages outside the brain.

Sometimes haemorrhages can also occur outside the brain and within the skull (subarachnoid haemorrhage). The most common cause are swellings (aneurysms) at damaged areas in the blood vessels mostly as a result of arteriosclerosis. They become increasingly bigger with the danger of bursting and causing internal bleeding. These 'bulges' usually cause no symptoms. Often they have been there for a long period of time already and are frequently only discovered by chance during a routine examination.


Risk factors for a stroke.

Anyone can have a stroke. However the risk increases with advancing age. About half of all strokes affect patients over 75 years of age. There are certain risk factors which cannot be changed such as gender (men are more at risk than women), age or hereditary disposition. Other circumstances on the other hand can certainly be influenced or changed. If several of these factors concur, then the risk is even higher.


Diagnostics & Therapy

How is a stroke detected and treated? Read more about diagnostics and the treatment in our hospitals.

Diagnostics & Therapy

Stroke. Precautionary measure

There is no sure option for preventing a stroke. However there are things you personally can do to minimise...

Precautionary measure


Specialised Clinics

These clinics specialize in the treatment of a stroke and neurological diseases.

Specialised Clinics