In a sense, a stroke is many different things – with a single underlying cause: the cutting off of the blood supply to a particular part of the brain. Deprived of oxygen and nutrients supplied by the blood, brain cells quickly die, and when they do, the parts of the body controlled by those cells stop working. A stroke victim may thus lose the ability to speak or understand, he may become paralyzed or stop breathing altogether. The location of the loss function and its severity depend on the part of the brain that has been injured and on how badly it has been damaged.
In the majority of cases, the blood supply to the brain is interrupted by one of two major causes: a blood clot may block an artery leading to the brain or an artery may break. In the latter instance, the artery not only fails to deliver blood to certain brain cells, but the blood it releases can itself damage and kills additional brain cells.
The most obvious symptoms of a stroke are rather sudden inability to perform certain activities well or at all. Sudden weakness or paralysis or certain muscles can be one sign of a stroke. This is especially true if only one side body is involved. That is because a stroke affecting the muscle-control center in the right side of the brain will, in turn, affect only the action of muscles on the left side of the body and vice versa.
Other signs that a stroke sufferer may have had stroke are sudden blindness in one or both eyes or a sudden inability to speak clearly or at all, or to understand speech. When the last two symptoms occur together the condition is called aphasia.
Less obvious symptoms that might lead you to suspect that a stroke has occurred include reports of blurred or double vision; a sudden severe headache; confusion; dizziness; numbness, weakness or tingling in a hand or arm, foot or leg, or in one side of the face. But whether subtle or striking, any possible indication or a stroke should be urgently checked by a doctor or a specialist to whom the patient is referred. This is important: immediate medical attention can often mitigate the outcome of a stroke. It is also important to be aware that any or all of the symptoms of a stroke may vanish before a visit to a doctor; nevertheless, he should be seen anyway. The symptoms may have been caused by a transient ischemic attack, an important warning the doctor can act upon so that more serious ‘accidents’ can be averted in the future.