Hello Ma am I ve gone through the details provided by Uou. I want to tell you that your symptoms are falling in category of orthostatic hypotension. In this , you feel dizzy blurred vision , muscle weakness jus after you stand up or changes your posture. It is advisable when you are going to stand up just stretch and relax your feet for couple of minutes that will really help you out . It can also be related to some underline problems like low blood sugar, anaemia and dehydration. For this get you blood workup done, evaluate anaemia and sugar levels. Eat healthy and drink plenty of fluids. It s advisable to see your doctor if you experience frequent symptoms of orthostatic hypotension because they sometimes can point to more-serious problems. It can be helpful to keep a record of your symptoms, when they occurred, how long they lasted and what you were doing at the time. Good Luck