Seeing stars after standing up quickly from a sitting or lying down position is most likely due to a form of low blood pressure called orthostatic hypotension, according to Healthline. This is usually a temporary sensation and likely doesn't constitute an underlying health condition, according to Mayo Clinic.
If a person frequently feels dizzy or light-headed after standing up, it may be cause for concern, especially if the individual experiences fainting episodes, explains Mayo Clinic. Additional symptoms which may accompany orthostatic hypotension include blurred vision, nausea, weakness and confusion. Mild cases can be caused by exposure to hot climates, a drop in blood sugar, standing for long periods of time, dehydration or time spent in a hot tub. Elderly people are especially prone to feeling dizzy after eating meals. Orthostatic hypotension is a relatively common occurrence and develops when the body's blood supply suddenly travels from the head and collects in the legs.
These incidents may be caused by thyroid complications, Addison's disease, hypoglycemia, heart disease, bradycardia and diabetes, notes Mayo Clinic. The body's nervous system helps to regulate a person's blood pressure, and it is possible for underlying nerve disorders such as Parkinson's disease and multiple system atrophy to disrupt this function, resulting in low blood pressure.