In some cultures in the Northern Hemisphere, the astronomical March equinox (varying between 19 and 21 March) is taken to mark the first day of spring, and the Northern solstice (around 21 June) is taken as the first day of summer. In other traditions, the equinox is taken as mid-spring.
Circulation problems that cause dizziness. You may feel dizzy, faint or off balance if your heart isn't pumping enough blood to your brain. Causes include: 1  Drop in blood pressure.
Increased heart rate when you stand up from a resting position. You see, your heart pumps blood to the brain when it beats. If there's a sudden and dramatic increase in pulse rate, not enough blood gets to the brain and you get dizzy. So the increase in pulse and dizziness upon standing are key for diagnosis.