What role does hydration play in Preventing infection?

Fluid is so important in the body that even when levels drop only slightly, we begin to feel the consequences. Low levels of fluid in the body can cause headaches, feelings of dizziness, lethargy, poor concentration and a dry mouth.
If you aren’t getting enough fluids, your body may have difficulty regulating its temperature. Even small fluid losses can contribute to increased body temperatures.
Over a longer term, dehydration can cause constipation and can be associated with urinary tract infections and the formation of kidney stones. Good hydration is critical to health and keeps our bodies performing at their best, not only in terms of all the processes that go on but also keeping our levels of concentration up. Proper hydration can help the skin and mucous membrane cells act as a barrier to prevent bacteria from entering the body.
Adults need to drink around 1.5–2 litres of fluid a day. A typical mug or glass is about 200 millilitres (ml) so this equates to 8-10 drinks a day. Children need slightly less and should aim for around 6-8 drinks a day, but once they reach teenage years their requirements are similar to adults. The best advice is to keep a bottle of water close by to top up fluid levels regularly and keep thirst away.