Dehydration can affect anyone at anytime. It can manifest after you've been exercising or even during periods of inactivity. There are many causes of dehydration including malnutrition, diarrhea, vomiting, blood loss, and simply not replenishing fluids lost from urination and sweating. Fever from disease or illness can also trigger dehydration, which is why it's important to drink plenty of liquids when you're sick.
Dehydration begins with increased thirst and can quickly progress until it becomes a life-threatening emergency.
As cells begin to dehydrate, an abnormal thirst sets in. Heed this sign immediately. Drink water or, better yet, electrolyte-filled fluids such as Gatorade. These liquids can replenish cells better than water. Avoid caffeine of beverages with high levels of sugar, as they worsen dehydration.
When your body loses water, it has a harder time hydrating the skin and hair, and the tissues become less elastic. Test your skin by pinching it. If the skin takes a long time to return to normal, you're probably dehydrated.
Flushed skin is markedly red and not confined to the face and cheeks. This is a critical symptom of dehydration.
When your body lacks fluid, waste products become more concentrated in the urine and cause it to darken. Rule out other factors that could cause dark-colored urine, such as other health conditions or certain vitamins and minerals.
As the cells in your body lose fluid, the saliva in your mouth and throat dries up, which in turn dries out the mucous membranes.
Weakness or fatigue
Muscle weakness, or mental or physical fatigue, is also a symptom of dehydration. Fatigue can be caused by jet lag, mental stress, depression, activity, boredom, lack of sleep and disease. Vitamin or mineral deficiencies can be other causes.
Exposure to cold or shivering with a feeling of coldness can also be caused by dehydration.
Limited amounts of liquids in your body can cause you to feel dizzy, faint, or light-headed when you stand up, due to a drop in blood pressure.