Not drinking enough water: Keeping yourself dehydrated during periods can lead to cramps and discomfort. During periods, you experience hormonal fluctuations and a bloated belly. As your estrogen and progesterone levels recede, your body retains more water. This may impact your digestive system and causes constipation, gas, and bloating. Drinking at least 9 to 10 glasses of water a day during your period helps in fighting the bloatedness as it flushes waste out of your system.
Weakness during menstruation is usually caused by dehydration, due to the loss of fluid and blood
that occur during your period. This is probably not worrisome, though. The best way to counteract menstrual-linked weakness is to drink plenty of fluids, especially those containing electrolytes, such as Gatorade, Powerade, or other sports drinks. Water is also a good way to stay hydrated during your period. In addition, be sure to eat healthfully, and don't go for long stretches without having a snack or small meal. Eating properly during your period can help prevent hypoglycemia (low blood sugar), thereby preventing any additional weakness. Dehydration is the more important issue, though.