A clot is a sticky mass that develops when blood thins or dries up. When blood clots, it thickens and creates a lump. The blood in the patient's body failed to clot. This can be because of decreased blood flow, especially to areas of the brain where many small blood vessels cluster together (such as in the cerebral cortex). It can also be caused by abnormal proteins that may be present in the blood. These proteins can cause blood cells to stick together in a way that prevents more normal blood cells from being able to enter the area of damage. Without treatment, patients with acute stroke will usually die within one month after the onset of symptoms. Treatment may include medications to reduce the risk of further seizures or strokes, physical therapy, or surgery. Recovery depends on how much of the brain was damaged at first by the stroke and what type of rehabilitation therapy is used. Stroke is the leading cause of long-term disability in the United States. Approximately 130,000 people suffer a new or recurrent stroke every year. Of these, 60% have some degree of disability and 20% are dead. As we know, mortality due to stroke is high because many survivors are not treated properly. Many recover some function but never regain everything they lost. Others continue to suffer permanent damage.