What is Stroke?
The above information is for your reference only. It cannot be used in place of a consultation with a medical professional nor as a basis of self-diagnosis or for treatment decision. Only your physician can provide you with accurate diagnosis and appropriate treatment.
1. Mayo Clinic. Patient Care and Health Information. Diseases and Conditions. Stroke. Overview. Available at: http://www.mayoclinic.org/diseases-conditions/stroke/home/ovc-20117264 (Accessed Jun 21, 2017). 2. NHS Choices. Health A-Z. Stroke. Overview. Available at: http://www.nhs.uk/conditions/Stroke/Pages/Introduction.aspx (Accessed Jun 21, 2017). 3. Seshadri S, Beiser A, Kelly-Hayes M, et al. The lifetime risk of stroke: Estimates from the Framingham Study. Stroke. 2006;37:345-350. 4. Piao CS, Gonzalez-Toledo ME, Gu X and Zhao LR. The combination of stem cell factor and granulocyte-colony stimulating factor for chronic stroke treatment in aged animals. Exp Transl Stroke Med 2012;4:25.
A stroke occurs when the blood supply to part of the brain is cut off or severely reduced. Like all organs, the brain needs the oxygen and nutrients carried by blood to function properly. If the supply of blood is stopped or restricted, brain cells in the affected area of brain are deprived of oxygen and nutrients, and begin to die within minutes . By the age of 75, 1 in 6 men and 1 in 5 women will have a stroke .
Based on the pathological progression and timing after the onset, a stroke is divided into 3 phases: acute, sub-acute and chronic. Generally, if a stroke is within 48 hours, it is acute. A stroke is sub-acute when it has been 48 hours to 6 weeks or to 3 months since its onset, and chronic stroke is beyond 3 to 6 months after its onset .