Thirst

• Thirst is a sign that the body needs more fluids. Water is always the best way to quench a thirst, because beverages like tea or soda will only further dehydrate the body with caffeine and/or sugar. In extreme cases of dehydration, the thirst may feel severe. However, mild dehydration can set in before the body even feels thirsty, so water should be regularly consumed throughout the day.
  
  

Fatigue

• The body requires an adequate amount of fluids to perform at peak condition. When it is dehydrated, blood volume can drop and the heart can't effectively supply the body with nutrients and oxygen. This can lead to a constant feeling of fatigue. Those who become dehydrated while detoxing may not ever feel well rested, even after a long night's sleep. Even regular daily activities can become difficult during a detox.
  
  

Dry Skin and Lips

• One of the most obvious signs of dehydration is dry skin and chapped lips. The skin can become easily cracked and shriveled without adequate moisture. As body fluids are lost through detoxing, a person might even appear prematurely wrinkled in the face. This is because the skin loses its elasticity when it is dried out. However, these superficial "wrinkles" can be improved with proper hydration.
  
  

Rapid Heartbeat

• Detox diets can lead to abnormal heart rhythms. As the body quickly loses water and becomes dehydrated, electrolytes become imbalanced. Electrolytes are important, because they regulate the body's nerve reactions and muscles. A low level of electrolytes can cause a rapid heartbeat or irregular heartbeat, which is potentially fatal.
  
  

Concentrated Urine

• Those who go more than six waking hours without urinating may be dehydrated. As the body runs out of water, urine flow decreases and becomes very concentrated. Dark, concentrated urine is a common sign of dehydration and if the urine remains that way, a urinary tract infection can develop.