Acute osteomyelitis refers to an infection which develops and peaks over a relatively short period of time. In children, acute osteomyelitis usually presents itself as pain in the affected bone, tenderness to pressure over the infected area, fever and chills.
Lotkowski said dizziness is also compared to feeling faint or lightheaded, and may be accompanied by nausea and skin clamminess. A drop in blood pressure which can occur after sitting up or standing too quickly could cause this, as well as inadequate output of blood from the heart.
this is why you get light headed when you are sitting and stand all of a sudden because when you are sitting your blood tends to pool up in your legs and standing all of a sudden sends a sudden huge burst of a lot of blood to your brain. your brain gets a little oxygen starved when you are sitting. Source(s):