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.
Cardiac syncope: Heart disease causes a person to faint by a variety of mechanisms. Cardiac causes of fainting are generally life-threatening and include the following: Cardiac rhythm abnormality (arrhythmia): Electrical problems of the heart impair its pumping ability. This causes a decrease in blood flow.