If you feel weak for no reason, there is a possibility that you don't drink enough water. Water is so important for your body, that you can increase your health considerably just by drinking the needed amount of water every day. Most people are actually semi dehydrated: this means their bodies do not get enough liquids and they experience health disorders because of that lack.
What effect water has upon our bodies? It is difficult to explain it in just a few lines. You can even say that our body is based on water. Water is in our every tissue and it is in every single cell. Many biological functions require a certain amount of water. Digestion, excretion, absorption and circulation are only few to mention. If you don't drink enough water these parts of our organisms can't function normally. System of hormones also relies on proper balance of water. Our brains need water as well. You have probably heard that a human can't survive without water any longer than two weeks. However serious damage for body is done after just three or four days.
What amount of water is enough to keep you healthy? It depends on your nutrition and your weight. If you drink other healthy drinks during a day (like fresh squeezed juices or green tea) you can drink less water. Otherwise you should consume about 1 liter of water for every 23 kilograms of your weight (or 1 quart for every 50 pounds of weight). That's the amount of water that keeps you healthy and feeling great. If you find it hard to count how much water you drink every day, take a jar and pour in the needed amount every morning. This way you will know exactly how much water you consume.
For some people drinking so much water looks an insane idea, but they probably suffer from dehydration. How to know if your body is dehydrated? The first symptom is thirst. Basically you shouldn't feel thirsty at all; when you do it means your body has already started to dehydrate. You can take a bottle of water everywhere you go to avoid this situation. You may say this can cause kidney or excretion system disorders, but our bodies need water and it is capable of ‘recycling' it. However if you have some health disorders, you should visit your doctor before you drink 3 or more liters of water a day. The other symptom of dehydration is dizziness. You can clearly notice this on hot days when suddenly you feel dizzy or even have a headache. This happens because even if you consume enough water in high temperature we sweat and lose a lot of liquids. That's why you should drink a bit more water during hot days or if you go in for sports. If dehydration lasts for several days, you can feel more unpleasant symptoms. Different parts of your body need water; when you don't drink enough some parts begin to suffer because the more important parts absorb the water you drink. One of the first functions to feel lack of liquids is digestion and this can lead to constipation. If you suffer from this, you should weigh your nutrition and the amount of water you consume. Water is vital for many different parts of our bodies; if we dehydrate all these parts stop functioning sooner or later.