Dizziness, lightheadedness, and the feeling of passing out is a common complaint in patients who have low blood pressure.
When the blood pressure is too low, not enough oxygen-rich blood is being delivered to the brain, and its function can be affected. It lead you a fall. you have to learn how to monitor standing up, sitting on and lie down
Anemia (decreased red blood cell count)
Dehydration (loss of water in the body) often occurs with infections that cause vomiting and diarrhea. Fever also can cause a significant amount of water loss due to increased metabolic rate and excessive sweating as the body tries to cool itself.
Heat-related illnesses associated with dehydration such as heat cramps, heat exhaustion, or heat stroke (a medical emergency).